MSc Artificial Intelligence Track: Gaming Master Thesis Investigating the Relationship between FFM, Game Literacy, Content Generation and Game-play Preference by Norbert Heijne 10357769 24th October 2016 42 EC October 2014 - October 2016 Supervisor: Dr.ing. S.C.J. (Sander) Bakkes Assessor: Dr. F.M. (Frank) Nack Faculteit der Natuurwetenschappen, Wiskunde en Informatica Abstract Game mechanic generation has a large search space that contains many possible solutions that result in a viable game, but the game mechanics might not be preferred by the player. To guide the generation process we would have to be able to predict the game-play preference of the player. Game-play preference categorization is a relatively underexplored topic of investigation within the domain of game artificial intelligence. To see whether we can categorize game-play preference with user profiling, we investigated the relationships between personality, game literacy, experienced difficulty level and game-play preference. We have created a game based on ”the Legend of Zelda: A link to the past” which contains content generation for multiple gameplay elements. We gathered data via questionnaires and game metrics to investigate the relationships. Our data shows that personality and game literacy are likely indirectly linked to preference. However, experienced difficulty could not be linked to preference. 1 Investigating the Relationship between FFM, Game Literacy, Content Generation and Game-play Preference Norbert Heijne October 2016 Abstract Game mechanic generation has a large search space that contains many possible solutions that result in a viable game, but the game mechanics might not be preferred by the player. To guide the generation process we would have to be able to predict the game-play preference of the player. Game-play preference categorization is a relatively underexplored topic of investigation within the domain of game artificial intelligence. To see whether we can categorize game-play preference with user profiling, we investigated the relationships between personality, game literacy, experienced difficulty level and game-play preference. We have created a game based on ”the Legend of Zelda: A link to the past” which contains content generation for multiple gameplay elements. We gathered data via questionnaires and game metrics to investigate the relationships. Our data shows that personality and game literacy are likely indirectly linked to preference. However, experienced difficulty could not be linked to preference. 1 Introduction Procedurally generated content (algorithmically created content while playing) has been used in many games to make the development process more efficient by reducing design costs (design of a game’s environment and the level content within those environments). In the genre rogue or rogue-light game genre a player is often confronted with the same environments because the player is forced to start over when the player fails to complete the game during that try. In these kinds of games procedural generation of the environment is often mandatory to keep the game interesting and increase the replay value. 2 Personalisation of games has also become more prevalent, this usually consist of influencing the game’s difficulty settings based on the performance of the player, which allows many different type of players to play the game at their own level. Some games offer settings with which the player can tweak the generation of content, examples of this are found in level generators for strategy games where the player can set the frequency with which some elements of the game occur. Another layer of generation is the game mechanics generation where a game’s set of rules are determined by an algorithm. Currently however this type of generation has been mainly used to discover new types of games or more interesting variations on existing types of games by manipulating the set of rules which defines the game, an example is the board game Yavalath [6] which came into existence through game generation techniques. Game design formalization [27, 18] has added to the development of tools for game mechanic generation but using game mechanics generation during game-play still has a large underlying problem. The large, sparse and chaotic search space for valid game mechanic rule combinations presents numerous challenges. Many rules are valid but not all are interesting or easily understood, since the player’s understanding of the game mechanics and subsequent appreciation are the determining factors on whether the game is actually fun. Combining the above techniques could result in more interesting gameplay, where not only the environment changes but also the underlying elements change slightly with each play-through. For this we would need a formal definition of what is fun and interesting about a game. Through common sense we already know that different people favor different types of games. There are few games that everyone will like. Whether a game lies within a player’s preference depends on the required time investment to get to a level of enjoyability that the player expects from the game, the steepness of the learning curve, the amount of actions required within a certain time frame and the amount of game conventions that it builds on [19]. A too high of a requirement on any of the above factors could prevent a player from enjoying the game [17]. This is why personalisation for games is important. If a game would be flexible enough to allow all kinds of players to get their preferred type of game-play, it would likely benefit from it. It thus becomes apparent that some form of player profile should be constructed for the game mechanics generation to determine which game mechanics should be used as the starting point and which parts can or should be changed. Without a direction the game mechanics generation would be 3 no better than randomly changing the mechanics of a game’s element. Even in the case of procedural content generation player profiling could prove useful in directing the parameters of a game’s generated elements into a direction that is more preferable to its player. Even with many games implementing some form of procedural content generation, a way of evaluating the generation process should be very welcome [13]. To investigate whether we can apply player profiling to direct game mechanic generation we will first have to try this in a more limited setting. Instead of going directly to the game mechanic generation we still need a platform on which we can gather data and which is limited enough in scope such that we can complete our research goal without adding too many technical challenges. Therefore there will be a focus on personalised procedural content generation and dynamic difficulty adjustment instead of game mechanic generation. 1.1 Research Questions To see if we can categorize game-play preference with user profiling we would have to investigate a broad set of metrics which relate to the user profile of a gamer. To see if this could also be used in an algorithm that would not require any non-game metric input then the preference categorization would also have to be retrievable with in-game metrics. To complement our in-game metrics we would also have to implement a form of adaptable difficulty to see if the amount of challenge a game element brings has influence on the preference for such a game element. To investigate this we would have to include the following types of metrics: • Game literacy metrics, which are composed of game preference metrics to represent the history and preference toward certain types of gameplay and gamer type metrics to indicate the amount of accumulated practice and game knowledge. • Personality scores to see if behavioural patterns transfer over to ingame behaviour. • Game metrics, which are composed of behavioural metrics and performance metrics. • Preference metrics, for each game-play element we would have to measure the preference to be able to investigate any possible categorization. 4 By cross checking these metrics we will investigate the influence between each of the metrics and their influence on preference. To answer our question if we can categorize game-play preference with user profiling the following questions would have to be answered: Problem statement: Can we categorize game-play preference with user profiling? RQ 1: Can we link performance to preference? RQ 2: Can we link personality to preference? RQ 3: Can we link difficulty preference and game knowledge to preference? RQ 4: Should a game generation algorithm also focus on dynamic difficulty adjustment? RQ 5: Can we create a game that enables us to gather data to test the possibility of these links and the dynamic difficulty adjustment? RQ 6: If any links can be found is there a viable player profiling solution among them? 2 Key Definitions Procedural content generation: PCG is a well applied practice in many games to date, this includes the generation of assets (textures, meshes, sound etc.), environments (levels, lay-outs) and animations (sprites, inverse kinematics). Non-player character : An NPC is a character in the game which can be spoken or interacted with and that is not controlled by any person. Dynamic difficulty adjustment: DDA is the application of a system that adapts the difficulty while playing. Game engine: A game engine is a piece of software that determines how a game should be programmed and what the possibilities are. The engine communicates with underlying processes of the computer that runs the game. This allows the programmer using the game engine to focus on implementing the actual game. 5 Game assets: Building blocks of a game, for example music, sprites (image sets which depict multiple frames of a 2D animation), tile sets (images that contain multiple smaller images which can be used to create the environment), sound effects, enemies / NPCs / the player character (a combination of sprites, sound effects and programmed behaviour). Hardcore gamer : A hardcore gamer is for our intents and purposes a video game hobbyist, one which spends or has spent a lot of time per week playing video games and which prefers more challenging games. Hardcore gamers are more likely than casual gamers to have a higher competence level for playing games in general. Casual gamer : A casual gamer is for our intents and purposes a video game enthusiast which does not have a lot of time to play games or does not want to invest too much time into playing games, as a result a casual gamer is more likely to have a lower competence level for playing non-casual types of video games and would be more drawn to casual types of games (mobile games, online mini-games). Action Role Playing Game (ARPG): A video game genre that entails that the player takes the role of a character in a story with real-time combat mechanics. RPGs in general usually have some form of quantification of the characters strengths and weaknesses, where the character gets stronger the further the story progresses. Player profiling: Creating a model based on the player’s characteristics and/or behaviour. This is used in making predictions about players or to categorically classify them. Trait based profiling: The Five Factor Model is an example of a trait based profile, each trait is considered independent of each each other and the traits are expressed in scales as opposed to categories. Type based profiling: The Meyer-Briggs Type indicator is an example of a type based profile, the measurements are translated into a type, a type being a categorical classification that represents the measurements. 6 3 Related Work In this section we will describe relevant papers for the three most important aspects of our research, player profiling by using personality traits or types, the reasoning behind and uses of certain types of content generation and the reasoning and possible implementations of dynamic difficulty adjustment. 3.1 Personality player profiling There exist many personality profiling tools and each tool has its uses. We will consider three types, the Five Factor Model (FFM) with facets, the First Demographic Game Design model (DGD1) which is strongly coupled with the Myers-Briggs Type Indicator (MBTI) and the BrainHex model which is based on the Second Demographic Game Design model (DGD2). The Five Factor Model (FFM) consist of multiple personality dimensions: openness to experience, conscientiousness, extraversion, agreeableness and neuroticism [29]. Each dimensions consist of multiple facets which zoom in on a particular type of behaviour or thought pattern within the dimension. Other research has also tried to find relationships between in-game behaviour and personality profiling. In this particular research [28] their correlation analysis showed relationships between the FFM traits and video game data, they concluded that a video game can be used to create an adequate personality profile of a player. The research has shown that the relationship between behaviour and personality is present in games which strengthens the use of personality profiling as a metric to explore the game-play preference. We see another instance of player modeling and relating game-play behaviour to FFM personality traits along with the facets of each FFM trait in other research [1]. By using trait facets and segregation of behaviour by location they greatly increased the power of personality to explain behaviour. An important lesson to learn from this research is to keep our situations clean from too much interference from other game-play elements to reduce noise in our data. Personality profiling has also been done in a broad setting using game genres [29]. The research showed that 2.6% to 7.5% of the game genre preference can be accounted for due to personality factors. Even with a low percentage like this the research points out that there are relationships between personality and gaming preferences, but that there are still unidentified aspects that impact the choice of games. As such this should focus the preference analysis on game elements instead of the game as part of a genre. There is other research which states that there are significant relations 7 between FFM dimensions and game genres [23]. It states that people who enjoy casual, music and party games tend to be more extraverted and that people who enjoy role-playing games, MMORPGs, action role-playing games, turnbased strategy and real-time strategy games tend to be less extraverted. Additionally, people who like sport, racing, flight simulation, simulation and fighting games tend to be more conscientious. Finally, people who like action adventure and platform games tend to be more open to experience. FFM dimensions have also been linked to game genres with estimations of underlying motivation based on the Player Experience of Need Satisfaction (PENS) measure. Relations were found between agreeableness and the feeling of competence from playing games. Openness to experience and the need for autonomy, which sees games as providing interesting choices and activities. The DGD1 model identifies four categories of players’ in game preferences and behaviours [20, 8]. These player types are the Conqueror, Manager, Wanderer and Participant types. Each player type is associated with particular personality traits using the MBTI. The Myers-Briggs types can also be transformed into FFM traits reliably [11]. The BrainHex model identifies seven categories, each with their own underlying reason for enjoying a game, the type of sensations that they pursue and consequently how they respond to those sensations [22]. The player types are Seeker, Survivor, Daredevil, Mastermind, Conqueror, Socialiser and achiever. BrainHex [5] is based on other research about type and trait based models, in particular about Myers-Briggs, FFM and their own development of a neurological based hybrid model in effort to create a more robust instrument. The underlying research mentions that game literacy and Openness to Experience (an FFM trait) are related to whether a player has the willingness to persevere in pursuit of victory, i.e. a gamer hobbyist (Hardcore gamer) instead of the mass market player (Casual gamer). The BrainHex survey [22] tells us more about the BrainHex model itself. Where they did a preliminary analysis of the Myers-Briggs types and how they relate to the types in the brainhex model. From this we learn that the research regarding this model is still ongoing. 3.2 Procedural Content Generation Procedural Content generation that would be relevant to the scope of personalised game mechanics generation are things such as generating interact-able objects such as story generation (narrative and conversations), characters, 8 items or enemy generation (comprised of texture, model, animation and behaviour generation), the environment generation (comprised of a mission and space generator) and generation of the tasks themselves such as puzzles or combat [3, 13]. Stories are also very hard to generate, multiple solutions are available such as using partial-order plans (POP) to represent stories. Or taking existing stories and representing the story as character actions. This is then coupled with natural language processing to create game-like stories [13]. It also states that currently this is still experimental and mostly used in an offline scenario. As such we will have to handcraft our own story to reduce our technical challenges regarding narrative and story. An example of the item generation is weapon generation, one way of personalising and bringing diversity into weapons is by adjusting the output pattern of an available weapon [12]. In this case the weapons were all ranged weapons that fired rounds in a distinct pattern, that pattern was evolved using evolutionary algorithms based on the behaviour of the player. Task generation such as puzzle generation is usually done through search algorithms. An initial state is generated, this state is tested if it is solvable, if it is not then a new state is generated by applying changes. This usually also needs to adhere to some difficulty setting which creates multiple layers of searching through the solution space. An example of this is the Lunar Lockout generator POGGI [15] or the sokoban problem generator by Murase et al. [21]. Search algorithms can be expensive to add to a game, especially when it is unknown if a viable solution will be found that adheres to the constraints such as complexity, difficulty and space requirements. This adds significantly to the technical challenges and as such we will most likely implement a more simple version. Our mission generator is based on research by Dormans and Bakkes [9] which described a method of using a replacement grammar on a graph structure and by doing this ensuring validity of the graph with each transformation. We have taken the basics of this system, the grammar and graph structure to produce our own level representations. Although the initial intent was to have a procedural setup for the space generation of the levels, it became clear that we would get results with less noise by creating a more static but predictable generation of the layout. 9 3.3 Dynamic Difficulty Adjustment A system to adapt the difficulty while playing is called Dynamic Difficulty Adjustment (DDA). Usually limited to a specific parts of the game (combat difficulty, puzzles used or resource parameters such as available life or ammunition). For example in the game Resident Evil 5, the game’s difficulty is set beforehand via the difficulty setting, and then the player performance determines an offset from the initial setting. Personalised difficulty systems are often preferred over static systems when done correctly [3, 4]. The initial difficulty should be set to a global safe setting, a setting that almost everyone can play and finish [4]. This ensures that the game can adjust accordingly without the player abandoning the game because of the difficulty. The Flow model [14], which tries to balance the difficulty based on the skill of the player is applied in our fight generator. The type of difficulty adaptation action that we take is ”Proactive”, we adjust the oncoming fights and puzzles based on performance of previous fights and puzzles along with our assumption model on how difficulty should fluctuate. We opted out of ”Reactive” adjustments to difficulty, such as changing an enemy’s health during a fight, because this does not make sense in our game’s conventions and we assume this would likely confuse players. In research there is also support for the hypothesis that a player is forced into a cognitive state that approximates the flow state during game-play [8]. The game would require a cyclical balance of skill and challenge. The player’s skill and resulting challenge relates to the overall complexity that is related to the information that the player has to his or her disposal and the amount of new information coming in. New players that have no concept of Zelda or ARPG games will most likely not go into a flow state because the amount of new information is too much of a challenge. Another form of DDA with regards to combat is dynamic scripting [24], where the internal decision making of the enemies is generated using a rulebase and this rule-base uses online learning to update the rules’ weights based on the actions of the player. This grants an advantage over increasing the number of enemies or changing the statistics of the enemies. When a player is sufficiently skilled, often the enemies become trivial because their behaviour does not change. When a player is a novice the game can be less overwhelming because the way the enemies interact can remain simple. To make the DDA for combat complete the enemies would have to work together to combat the player, often by having the individuals perform better they would still not take advantage of each others strengths or cover 10 their allies weaknesses. Learning your role within the team can improve the performance of the AI as a team and as such create more varied challenges for the player [2]. 4 Research Focus and Limitations To make this research project feasible we will have to place limitations on multiple parts of our research. Because game mechanics generation for a specific genre is a research subject by itself. However, our research is aimed at underlying principles of user profiling and preference, as such we will limit ourselves to procedural content generation within a narrow genre of games. Any elements of the game that we cannot easily generate will have to be designed by hand and emulate content generation to a certain degree. With these limitations we can focus on player profiling in a more controlled environment without having to deal with additional technical challenges. 4.1 Research Focus and Limitations overview In the following sections we will describe how we will direct our design such that we are left with a task which is feasible. We limit our task by employing the following: • We restrict our research to content generation instead of game mechanic generation. • We will employ a form of dynamic difficulty adjustment for all puzzles and fights. • Reuse of the assets and conventions that are available. • Using game design instead of complex generation algorithms. 4.2 Content Generation In this research we apply content generation techniques to emulate the game mechanics generation possibilities as much as possible. Such that the data and results that we acquire can be applied to the game generation case albeit in a limited scope. Our content generation will focus on levels and its content, fights (enemy spawns and placement), room contents (props and walkable space) and puzzle generation (chosen from three puzzle types). 11 4.3 Dynamic Difficulty Adjustment Our implementation of a DDA system will focus on the difficulty of the combat by determining the type and amount of enemies spawned for a fight. Puzzles have difficulty levels with predetermined settings for each type of puzzle. We also try to keep the increase in difficulty by other factors stable within a level. 4.4 Legend of Zelda Assets and Conventions Figure 1: The Legend of Zelda: A link to the past. The game The Legend of Zelda: A link to the past, a type of Action RPG, takes the player on an adventure that entails rescuing a princess from a dungeon and subsequently going on a quest to save the kingdom from ruin. The player is confronted with increasing challenges throughout the game requiring either reflexes and hand-eye coordination or solving a puzzle with logic and wit. The game carries conventions that have been very successful within the Action RPG genre of which the most prevalent are these: • Combat is done with some kind of weapon (often close range), with the player having only a rudimentary control over the weapon (a button causes a specific attack animation). The player then complements the rudimentary combat with tools and items found in the world. 12 • The hero has statistics with which the player can track the current strength of the character (life points displayed as hearts and magic power displayed as a green bar, see figure 2). • When the hero has zero life points left it is game over. • The hero gets stronger as the game progresses, either through an increase in statistics or available tools. • The world contains secrets to find which are often unlocked through the use of an item, tool, solving of a puzzle or defeat of a stronger than usual enemy. • The story often sends the hero to a dungeon (an enclosed area that is often hostile) which is riddled with enemies and traps and ends in a climactic boss fight (a much stronger enemy which often requires the use of the item found in the dungeon to defeat it). • Characters within the story often give hints on how to play the game or how to proceed with the story. The game that we made is based on the actual game The Legend of Zelda: A link to the past, it uses roughly the same game mechanics and conventions, albeit that we will generate our levels algorithmically and as such will contain less depth than levels with thoroughly thought out game design. The thought behind this is that we are more likely to improve player experience by using assets (e.g. characters, tile sets, enemies ) that are already deemed successful and carry many conventions that are known. In contrast to starting from scratch and emulating these conventions. On top of that the Action RPG genre uses many different kinds of elements, which widens our scope and potential data. Because the assets are taken from a well known game, nostalgia could influence the player’s rating of parts of the game and knowledge on the mechanics of the game could influence performance. To get better insight into which players might be influenced we added a question to the demographic questionnaire that covers if they have played The Legend of Zelda: A link to the past before. 13 Figure 2: Screen-shots from the game The Legend of Zelda: A link to the past, from top-left to bottom-right: fighting on a bridge, walking through the village, receiving an important item, fighting a boss. 4.5 Game Design Many parts of our game could not be generated because they are either too hard to generate or there was no research or algorithm available that could run efficiently with our chosen game engine. In this case, game design is used to hand craft scenarios (e.g. the village) or to craft smaller elements (e.g. enemies, hazards or props). These elements will then be used within the generation process. The village was handcrafted, this includes the items that are attainable, the NPC conversations, NPC placement and the story that is being told. We attempted to create an enjoyable story, such that the players who are 14 more interested in such a story would not be disappointed. The village also enables us to properly measure differences between players in regards to story decisions and NPC interaction. Most of the assets were already supplied with the engine and where the supplied assets fell short, new ones were created. This required manual adjustment to get the right feel and impact on for example difficulty with enemies or hazards. The effects that we can measure in our research is limited to the quality of our design. For example, the assumption of the linearity of the difficulty scaling depends on a correct implementation of the enemy and hazard difficulty settings. 5 The Game: Dynamic Zelda Since the focus of this research is on PCG and the player’s preferences, it was in our best interest to make sure that all other aspects of a proper game were accounted for. It would be detrimental to this research if the game was considered to be just experimental. Surely a game with no sound, horrible graphics and only game-play elements that have not been tried and tested before would detract from any kind of flow experience. The decision to then use an already existing game becomes a logical next step. When this research began we opted for a game engine that contained most of these assets and game-play elements from the start. We stumbled upon the Solarus Engine [25], an open-source game engine that had implemented its own version of The Legend of Zelda: A Link to the Past [26]. Compared to other platform that is often used, Infinite Mario, it had more to offer in terms of game-play variations. Zelda games often contains combat, puzzles, story elements, exploration and is an iconic title that most gamers would recognize. The engine has a relatively low cost to run the game in terms of processing power and has many elements and conventions already implemented that many players would be familiar with. As such we opted to turn this into something that would implement PCG. 15 Figure 3: Flow of the game. 5.1 The Game Flow The game’s structure is set up as followed: • The village: A place where the player is introduced to the quest, has the opportunity to learn more about the background of the characters and prepare for the journey ahead. • Tutorial Level: A level with no exploration options or extra resources, it contains four combat rooms and one of each puzzle at the lowest difficulty. • Shop: The shop houses a choice of equipment pieces that could simplify certain tasks, primarily tasks that involve getting hurt such as the mazes, the moving floor rooms or the fights. These pieces can be bought with money found in the levels. Exiting the shop transports the player to the next level. • Levels: A themed segment is made up out two levels with a generated layout in a particular theme that contains rooms that either generate combat, puzzles or a treasure chest. This is the main part of the game. After completing a themed segment, the player is transported to the shop. There are three segments in total. • Boss fight: A typical boss fight for a Zelda game, this is handled by our combat generator. • The village again: The player rounds up the quest with a choice on how to fulfil the quest requirements and completes the game. 16 5.2 Village Figure 4: The Village. The Village (figure 4) is where the player starts his adventure, the player is spawned near A2 with sinister music playing in the background. The player is now motivated by the player character’s father (A2) to go and seek help from the witch (C1) to cure the player character’s brother (A1) from his illness and is given the instruction to head east to ask her for help after picking up the Sword and Shield from the shed. Some of the NPCs are placed specifically to allow players to prepare for the oncoming journey. These include the shopkeeper (B1) which sells apples to the player, which restores 1 heart of the players health pool. The boy who lost his milk bottle (B8) reveals that he lost his bottle and asks the player to find it among the bushes. The player gets to keep the bottle when he finds it, which can later be used to fill it with potion from the witch to attain background information on the witch and to contain fairies which revive the player on death. To complete the game after acquiring the ”Cure Flower” quest item, the player has to talk to the brewer (B6) or the witch (C1) to make the cure. The brewer will do this for free, and create a strong cure. The witch will ask the player for 50 rupees and creates a diluted cure. Both will cure the 17 illness of the brother, thus the choice is there for flavor. When the player presents the cure to A1 the game’s credits roll and the game is complete. All other NPCs are non-beneficial and only add flavor and background information to the game. The Village is built in such a way that little interaction is required and that conversational content can be ignored if the player wishes to follow the instructions as fast as possible. 5.3 Level Generation In this section we will present all the parameters used when generating a level and how a level is generated. The levels are built in four steps: • A level’s content is first generated as a graph representation which is called a mission. The mission only has information on the connectivity of rooms, their type and the content of the chests. The generation process is based on the mission generator in [9]. • Spatial planning is laid out using the maze generator that prioritizes placing rooms such that the level always stretches outward. Pathways inside the rooms are also laid out using the maze generator. • Assets are places, for the forest and swamp levels the tree background is generated, for the cave the walls, floors and doorways are generated. Afterwards any space left that was designated as non-walkable is filled with static props, throw-able props (bushes or rocks) or hazardous tiles (such as water or holes). • Barriers are placed, such as bushes and rocks that block specific entrances. Treasure chests are placed. 5.3.1 Level length settings The parameters used in generating a level can be found in table 1. A themed segment (Forest / Swamp / Caves) consists of two levels. A level has a main length of rooms which are either a puzzle or fight, added to that is a start and an end room and the first level of a segment has a room with a treasure chest halfway through the main path that holds an item with which the player can destroy the new type of barriers in that segment. Each themed segment has a new type of barrier and also spawns old barrier types. 18 Figure 5: Level layout and use of the level length parameters for generating a level An optional path entrance is placed just before the treasure room or the halfway point that is blocked by a new type barrier, requiring the player to go back in the first level of a segment if they want to explore. Each room in the optional path opens up a path to a branch that has a specific number of rooms before entering a room with a treasure chest that holds 100 rupees. In the second level one of the optional treasure chests contains a heart container. Level name Tutorial level Forest 1st level Forest 2nd level Swamp 1st level Swamp 2nd level Caves 1st level Caves 2nd level branch length N/A 1 2 3 4 5 6 optional path length 0 2 2 2 2 2 2 main path length 7 4 4 4 4 4 4 Barrier type bush rock rock large skulls large skulls bomb-able blocks bomb-able blocks Table 1: The length parameters (amount of rooms) for generating a level. The purpose of the linearly increasing branch lengths is to increase the time between the payout of the extrinsic rewards and to avoid a ceiling effect 19 when it comes to the number of explored optional rooms. 5.3.2 Mission generator The underlying mission generator is used primarily to generate a graph that can be used within our generation process. It uses the parameters and generation process described in the previous section. During development the generic implementation of the mission generation found in the paper [9] was changed to generate more static levels, in which we could specify the branching such that the level would not generate vastly different maps, which would detract from our experiment and to prevent the generation from going out of bounds of the map’s allowed measurements. The mission generator still uses the same principle as described in the paper, a graph representation is used with directional and bidirectional relations, and the nodes in combination with the relation determine what the node represents in our generation process. Since we wanted to avoid stringing together multiple of the same tasks after one another (alternate between fight and puzzle) such that the player is not bored with too much repetitiveness and that the main path always contains the same amount of fights and puzzles such that we will get about as many results for fights and puzzles; during a level with a specific difficulty in the case of static difficulty this is even more important as it keeps our data comparable between levels. Once the mission generator parses the graph representation we have our mission representation, which contains the data for rooms and their connection to other rooms, barrier placement, for chest rooms their chest contents, start and exit rooms as well as the overall level information about difficulty, theme and type of map (tutorial, normal or boss). This data is sent to the space generator to generate our level layout. 5.3.3 Space generator Our space generator uses the Maze generator to produce the layout of our level, the map. The Maze generator takes in three parameters: Wall width (x pixels by y pixels), corridor width (x pixels by y pixels) and total maze measurements (x corridors by y corridors). The maze generator supplies us with a grid where each node contains information on which wall is open, closed or contains a small pathway to the other node. Starting with the entrance area at the most western room in the middle of the ”maze” we assign the room its number that is associated with a room in our mission representation and we assign the connected rooms to the 20 Figure 6: Visual representation of the maze generation parameters adjacent rooms that has the most space left (a random pick between the room with the most adjacent unassigned rooms in 2 degrees, see fig. 7). Connections to other rooms are designated as a small pathway, if a room is larger than one node the walls between the nodes are designated as open. Figure 7: Placing a room within a grid. Grey is an already present room. Green, Red and blue indicate possible locations, the colored rectangles signify the unassigned rooms in 2 degrees. 21 Fight rooms are square and take up the size of one room, puzzles need the extra space to be viable as puzzles and take up the size of two rooms. Boss rooms are also square but take up four rooms. We now have a grid as our spatial representation with which to further improve our layout. The next step involves carving paths inside the nonpuzzle rooms (puzzle rooms need all the space available). For this we use the Maze generator again. We first create a grid of the room with the corridor size of 16 pixels by 16 pixels (the size required for our character to be able to walk through), we then subdivide our room over the length and width into sections, and use the center cells (with a random offset) of each section to use our maze generation algorithm on. Using the smaller section representation we use path-finding to open up cells from each center cell to another cell where the section representation indicated that there is an opening. The opened cells are widened resulting in a pathway that connects the entrance with all exits in the room, the still unopened cells in the grid are used for prop placement. 5.3.4 Placement of assets Our assets that we use are made up of sprites and tiles. Sprites are objects in the game that have an animation based on their internal state that can be interacted with by input of the player. Tiles are static and are placed on a layer, tiles cannot be interacted with but can affect the player (water, holes, spiked floor all cause damage); they can be arranged in a pattern to form a prop (for example a tree is made of tiles that are placed on multiple layers in a pattern). We created many of these props to be used together with each theme. The produced spatial representation of the previous section is used to fill the level with sprites, tiles and props. In case of the Forest and Swamp themes the walls and non-walkable sections are filled with trees that are placed in a repeating pattern that is common in the The Legend of Zelda: A Link to the Past. These trees are only placed if there is space to place an entire tree. The remaining nonwalkable space in the rooms is filled randomly with either water (the player jumps a certain distance when touching the edge of the water), throw-able sprites (bushes or rocks), smaller props or designated as empty space. In case of the Caves the wall props are placed and remaining space in the walls section is filled with a specific tile, which is also common for The Legend of Zelda: A Link to the Past. The non-walkable space in rooms is filled randomly with either spiked flooring (which damages and stops player movement), pits (where the player directly falls into, receives damage and is 22 placed back on the last spot where the player was safely standing), throwable sprites (mostly rocks), or smaller props. The change in asset placement is used to linearly increase difficulty besides the already present adaptable difficulty, as well as to provide a noticeable change in the way you can move around in the environment. A question on the overall feel of the level was therefore added to the in-game questionnaire to acquire insight into the effect of the themed props and placement. Figure 8: Themes: Top-left, Caves. Top-right, Swamp. Bottom, Forest. 5.4 Combat Generation Combat generation is done via the fight generator. There are two settings due to the experimental setup. A static linearly scaling difficulty and an adaptable difficulty. Both difficulty settings use a specific set of enemies. These enemies are displayed in the figure below. 23 Figure 9: The enemies: From left to right, Hardhat, Snapdragon, Minillosaur, Green knight. The enemies each have their own behavior pattern as well as some shared behavior: • The enemy types Hardhat, Minillosaur and Green knight moves towards the player once it is within 100 pixels of the player. • The player loses half a heart when the player’s character touches an enemy. • The enemy types Hardhat, Snapdragon and Green knight move about randomly before spotting the player. • The Hardhat repels the player backward when it is hit with a sword strike. • The Minillosaur starts out as an immobile egg, and cracks open once the player is within range. • The Snapdragon always moves about randomly in a diagonal pattern and ignores the player. • The Green Knight’s sword repels the player’s sword attacks, preventing damage but repels the Green Knight backwards. The static difficulty is handpicked and linearly increasing between levels, hardhats only spawn in the caves on this difficulty setting and the amount of enemies spawned are based on play-tests of ”average” players. 24 Level number Tutorial Forest Swamp Caves Enemy spawn combinations [M×4] OR [G×2] OR [S×3] [M×5] OR [G×3] OR [S×5] [M×7] OR [G×4] OR [S×6] [M×8 + H×2] OR [G×4 + H×2] OR [S×6 + H×2] OR [H×5] Table 2: The settings for static combat, H: Hardhat, S: Snapdragon, M: Minillosaur, G: Green knight. The adaptable difficulty is made with Flow experience [8, 14] in mind, balancing the enemy composition in a room in such a way that it tries to find the optimal weight per enemy type based on the player’s performance and actions using linear regression. The combat’s difficulty is then moved up and down in a sinus wave pattern such that the highest difficulty is the optimal difficulty given the player (A difficulty that the player would just about handle). We suspect that (hardcore) players that enjoy challenges would prefer the adaptable difficulty over the static difficulty because it presents a more suited challenge a lot earlier than the static difficulty and that casual players enjoy short combat with low difficulty and therefore would prefer the static difficulty in the earlier levels. Sadly our combat generator cannot differentiate between the two types of players because of the lack of data, as such players might quit because of the adaptable difficulty being too difficult or players might quit during the static difficulty in later levels when the difficulty becomes too much. To decrease the amount of noise in the difficulty of the combat we implemented resource drops in a deterministic way. The amount of hearts available to the player will determine the amount of mistakes the player can make and consequently the difficulty of the fight. If some fights would grant a lot of hearts and others none then it would be detrimental to our data. As such the loot table (see table 3 for details) is determined beforehand, an item is dropped from the loot table randomly with no returns whenever an enemy is killed or a throwable prop is picked up. When the loot table is empty it is refilled. Type of drop Amount Hearts 1 Arrows 2 Bombs 1 Magic 1 Single Rupee 4 Table 3: The loot table used for enemies and picking up throw-able props. 25 The boss always has a static difficulty (requires 6 hits with bomb explosions) and is relatively easy as long as the player has the convention of looking for a monster’s weakness, pays attention to auditory (any hit with a sword bounces off) and visual cues (small minions drop bombs) and reads the bomb bag acquisition description that the bombs are throwable or knows the Zelda convention that the boss is always beaten with the use of the last equipment piece found in the dungeon. The qualities that would help improve the player’s performance with combat are reaction time and planning. Timing sword swings decreases the difficulty of the Green knight enemies the most and is useful against all enemy types. Hardhats are more easily dealt with using items or throwable props. Using any type of item from the shop will decrease the difficulty of the fights. Timing the sword swings would indicate a larger precision and less sword swings overall. 5.5 Puzzle Generation A puzzle is generated when the player enters a room that has been designated as a puzzle room by the mission generator. Which puzzle type is generated is based on the amount of puzzles of each type has been generated, the type is then chosen randomly between the types that have been generated the least amount of times such that the generated amount remains the same but with random ordering. Like the combat generation we implement two variants of the difficulty, a static linearly scaling difficulty and an adaptable version. The adaptable version of the puzzle generation carries a simpler version than the combat generation. The difficulty increases or decreases based on the time it took to complete the puzzle, the life lost during the puzzle and whether the player has died during the puzzle or in the case of the sokoban puzzle type the player pressed the optional ”Quit puzzle” button. The cut-off points have been determined with play-tests of persons with average to high level of skill. The static difficulty was also determined with play-tests by taking the maximum attainable difficulty level of the play-tester with the lowest skill level as the ceiling of our linearly scaling difficulty. Details on the difficulty setting of a particular puzzle type can be found in the subsequent puzzle type specific sections. 26 5.5.1 Maze We create our maze in the designated room using Prim’s algorithm, this results in a maze without loops with a fixed start- and endpoint and random paths in between with a good amount of branching. The difficulty of a maze of the above type (no loops, completely random and with fixed start- and endpoints) is usually defined by the size of the maze which comes down to the combined length of paths that are most likely to go towards the endpoint in the maze. A maze is unlikely not to be solved when the player can see the entire maze and without loops in the maze a player can reach the end in a reasonable amount of time with just trial and error. In our game world we cannot make very large mazes without impacting the game’s flow and performance due to the nature of this research and the game’s engine respectively. Figure 10: The hazards present in the maze: left to right, fireball statue, bouncing hazard, reactive spike block, pit. As such the following features were added to increase the difficulty of the maze: • Darkness: the entire maze is covered in darkness and the player can only see a small area ahead of him. The player can use the Magic mirror item at the cost of magic points to illuminate the maze for a short time. • Pits: Some of the dead ends have black pits which cause the player to be transported back to beginning of the maze as well as lose life points. • Bouncing hazards (official enemy name is Bubble): These invulnerable enemies bounce their way through the maze and touching them causes the player to lose life and magic points. 27 • Fireball spitting statues: Another invulnerable enemy which shoots a projectile at the player roughly every four seconds, the player can use his shield to block the projectile or evade it through lateral movement. This projectile moves through walls in the maze. • Reactive spike blocks: Yet another invulnerable enemy which automatically moves at a fast speed towards the player when the player is directly horizontally or vertically aligned with the enemy and within a certain range, the enemy cannot move past the walls of the mazes. The details on the settings for static and adaptable difficulty can be found in table 5 and 6. The settings for generating a maze puzzle given a difficulty level can be found in table 4. Difficulty level Fireball statues Bouncing hazards Pitfalls Reactive spike blocks Darkness 1 0 0 No No Yes 2 1 1 Yes No Yes 3 2 2 Yes No Yes 4 3 3 Yes Yes Yes 5 4 4 Yes Yes Yes Table 4: The generation parameter settings of the maze per difficulty. Static Level name Difficulty Tutorial 2 Forest 3 Swamp 4 Caves 5 Table 5: The settings of the static difficulty for the moving floor puzzle. 28 Adaptable Hearts lost AND/OR Time spent (seconds) COP = 20 × (( difficulty +1)/2) ≤ 1 HL AND TS ≤ COP ≤ 1 HL AND COP < TS ≤ COP ×1.5 ≤ 2 HL AND COP < TS ≤ COP > 3 HL OR TS > COP ×1.5 > 4 HL OR death Difficulty change +1 +0.5 +0.5 -0.5 -1 Table 6: The settings of the adaptable difficulty for the moving floor puzzle. The amount of hearts lost (HL) or the time spent (TS) versus the cut-off point (COP) is used to determine the change in difficulty and the difficulty level rounded down is used. The likely qualities that would help in solving this puzzle type is reaction time to avoid spike blocks, pits, projectiles and bouncing hazards and planning to block the projectiles, which would indicate a relatively small amount of life lost and a larger amount of time taken. Reckless behaviour would most likely result in falling in pits, relatively large losses of life, but small amount of time spent on completing the maze. 5.5.2 Moving Floor The moving floor puzzle is a maze that has large corridors in which the floor moves in a particular pattern and speed and where touching the wall causes damage to the player, the player can see the movement of the floor and has full visibility of the environment. Figure 11: Examples of the moving floor puzzle generation within a level. Left has difficulty 3, right has difficulty 5. The likely qualities that would help in solving this puzzle is planning 29 and timing: The floor moves in a repeating pattern for a set amount of time at a constant speed with visual acceleration and deceleration, if the player positions the hero properly the player can maneuver through the puzzle without harm. However, reckless action by the player will result in constant harm from correcting mistakes while the floor continues to execute its pattern. The details on the settings for static and adaptable difficulty can be found in table 8 and 9. The settings for generating a moving floor puzzle given a difficulty level can be found in table 7. Difficulty level Corridor width (× character width) Speed Pattern 1 4 2 3.5 3 3 4 2.5 5 2 48 pixels per second Random between up-down / left-right / up-right-down-left Table 7: The generation parameter settings of the moving floor puzzle per difficulty. Static Level name Difficulty Tutorial 2 Forest 3 Swamp 4 Caves 5 Table 8: The settings of the static difficulty for the moving floor puzzle. 30 Adaptable Hearts lost AND/OR Time spent (seconds) COP = 20 × (( difficulty +1)/2) ≤ 1 HL AND TS ≤ COP ≤ 1 HL AND COP < TS ≤ COP ×1.5 ≤ 2 HL AND COP < TS ≤ COP > 3 HL OR TS > COP ×1.5 > 4 HL OR death Difficulty change +1 +0.5 +0.5 -0.5 -1 Table 9: The settings of the adaptable difficulty for the moving floor puzzle. The amount of hearts lost (HL) or the time spent (TS) versus the cut-off point (COP) is used to determine the change in difficulty and the difficulty level rounded down is used. 5.5.3 Sokoban Sokoban is an already existing game which entails the following: The object of the game is to move blocks on top of switches by pushing them with a character, there exist at least as many movable blocks as there are switches, the player wins when every switch has a block on top of it. The game depends heavily on the layout of the walkable space and the placement of the movable blocks and switches. Generating a Sokoban puzzle can be done via random generated layouts which are then tested for difficulty and feasibility by a bot [21]. Our game however relies on on-the-fly generation of puzzles and as such a generation pipeline would no longer be in real-time and goes beyond the purpose of our research. There exist many fun handcrafted puzzles which already have a generalized text format and therefore we use a downloaded set of handcrafted layouts [10] that are small enough to fit in our rooms and are generated in game by parsing the adjusted downloaded set and placing them in the room at which point our algorithm makes the layout playable. The adjustments have been made to the downloaded set: • An entrance and exit have been added, the exit is blocked by a wall, which opens up when all switches have blocks on them. All movable blocks and switches also disappear when the player completes the puzzle. • A switch was added at the entrance to reset the puzzle and teleportation tiles (which teleports the player on top of the reset switch) have been added at multiple spots instead of a wall, such that the player 31 can always reset the puzzle even if the player blocks off the path to the reset switch with a movable block. • Difficulty annotation has been added to each layout based on playtests. • The layouts that are similar and use the same trick to solve the puzzle have been grouped together and ordered in difficulty. An example of the layout and details on the handcrafted puzzles can be found in figure 12. Figure 12: Example of the Sokoban generation: Layout group 11, 1st in the group, difficulty 3. (#): Wall, (.): Switch, (@): Entrance, (E): Exit, ($): Block, ( ): Empty, (R): Teleport. The player always completes each group in order of difficulty and is not suddenly presented with a higher difficulty version while the player hasn’t completed the lower difficulty version. The layout used is randomly picked from the list of layouts of a certain difficulty where the layout is the first in the group or the player has completed the layouts that came before in the group’s ordering. When no layouts fit the criteria we look for layouts one level of difficulty lower and fitting the same criteria. If no fitting layouts are found, we pick a difficulty level higher than the current. The adaptable difficulty takes the difference between current difficulty and selected difficulty into account when deciding whether to change the current difficulty setting when the puzzle is completed. Sokoban is a type of puzzle that requires the player to spot the trick used to complete the puzzle, this can take a long while depending on the player. Being able to plan ahead is vital in completing these puzzles. We have therefore added a ”Quit” option for this puzzle where after a certain time a message is displayed on screen saying that they can press a button 32 to instantly complete the puzzle. This is to ensure that the research is not hindered by the player’s inability to solve the puzzle. The adaptable difficulty and logging both take the quit option into account. The details on the settings for static and adaptable difficulty can be found in table 10. Static Level name Difficulty Tutorial 2 Forest 3 Swamp 4 Caves 5 Adaptable Time spent (seconds) Difficulty change ≤ 90 +1 > 90 and ≤ 135 +0.5 > 135 -0.5 > 135 & pressed quit -1 Table 10: The Sokoban settings for the adaptable and static difficulty. In case of the adaptable difficulty level is rounded down when used. 5.6 Exploration Rewards and Shop Most games apply some form of extrinsic rewards to complement the intrinsic rewards of playing, completing a challenge or completing a non-mandatory task. The shop was added to give players more choice in their combat play style and to present extrinsic rewards for exploration. The player has a possible income of at least 300 rupees in between shops, with a bonus on top for killing enemies. All items cost 300 rupees to buy with the exception of Apples (15 for 3) and Fairies (50 for one). On top of that one of the chests in the second segment in between shops contains a full heart container which restores the player’s life points and increases the maximum life points a player can have. The following items were added to the shop: • Bottle: An extra bottle to carry an extra fairy, the amount of life the player has available is an indicator for how reckless the player can be before having to restock on life points. The player can only buy one extra bottle. • Fairy: Buying a fairy while the player has an empty bottle results in a bottled fairy which is released upon the players death, restoring the player back to life with full life. If the player has no empty bottles the fairy is instead consumed immediately, restoring the player to full life. • Three apples: The player can own a maximum of 10 apples, and the 33 player buys 3 at a time. An apple can be consumed by the player to restore one heart. • Magic mirror : The player can use this item at the cost of magic points to blind all enemies on the screen, effectively immobilizing them and during this time, contact with the enemies no longer causes damage. The player can also utilize this item to illuminate a dark maze for a short time. • Bow : The player can shoot arrows in a straight line either horizontally or vertically which kills normal enemies if it hits. The player can find arrows by lifting bushes, lifting rocks or killing enemies. The player can hold up to 10 arrows. Figure 13: Items in action: Top, bow and arrow. Right, fairy release after death. Left, magic mirror. 34 Figure 14: The shop. The shop also contains an NPC that asks the player to fill in an in-game questionnaire about the last themed segment they completed. The details of these questions can be found in the Appendix. The NPC, the shop and the in-game questionnaire also acts as a an interruption of the flow of the game such that the data gathered in the following segment is much less based on the feeling of the segments that came before. Although the time spent on the game would likely still have a large effect, given the average player’s time they can stay focused. 6 User Profiling Before we can find out if our user profiling can be linked to game-play preference we should first define it. The following sections will describe the elements that will be included in the user profile. It should be noted that the user profiling is meant to capture a broad area of measurements such that extremes on the measurements could clearly show us differences in preference, behaviour and performance. The user profiling will determine what kind of data we gather before the game starts and will be used in the analysis of the game metrics and the preferences. 6.1 Overview of the User Profiling In the following sections we will discuss the following: 35 • Personality test, which personality test should be used in our user profiling and what are the details of the personality test. • The assumptions and hypotheses regarding the following topics: – Game literacy – Personality influence – Preference of difficulty 6.2 Personality Test The following properties were taken into account while choosing the personality test to use: • Ability to compare with other related work to ensure that this research is relevant. • The scales available to be measured and specificity of scales. This is to ensure that overarching behaviour patterns that the scales represent can be related to behaviour logging. • Length of the test. A lengthy and time consuming test means less willing participants. • Established test, such that it has enough empirical backing to ensure the validity of our data. Most of the related work uses the Five Factor Model (FFM) or a test based on the FFM to measure personality dimensions [29, 1, 28]. Other options were present in the related work such as the BrainHex [22] which is specifically aimed at games, the downside is that it does not have specific behaviour related scales and presents a type based result which definitions are too broad, the empirical backing is also still being acquired. Another option was the Meyer-Briggs Type Indicator (MBTI). This personality test has a lot of empirical backing but presents a type model. In game studies the comparative failure of trait models is less than those of type models [5]. Because type models define a range rather than a point on a scale it could introduce noise into our analysis. As such the FFM stands out, the NEO-PI-R version [7] in particular since it has enough specificity with six facets for each of the five dimensions of the FFM and an abundance of empirical backing. The NEO-PI-R is a commercial product however and has a very lengthy test. Thus we opted for 36 a publicly available version that measures the same constructs as the NEOPI-R but with a bit less precision and a third of the amount of questions. The IPIP-NEO-120 [16] is a personality test that consist of 120 questions which all give a score relating to one of the five traits and one of the trait’s facets. 6.2.1 FFM Traits The FFM models personality using five traits and explained using the OCEAN mnemonic as explained in [29]: • Openness: This factor refers to openness to experiences. People with high scores tend to be imaginative, prefer variety, have aesthetic appreciation, show intellectual curiosity (not necessarily intelligent), keep close attention to their emotions, and embrace new ideas. On the other side of the spectrum, people with low Openness scores are more conventional, prefer known situations, the expression of emotions are minced, and their array of interests is narrower. • Conscientiousness: This trait is related to the capability of self-control. When a person has a high Conscientiousness score, she is well organized and reliable, can identify clear objectives, plan accordingly, and has strong will. A low score indicates that people have more difficulties in achieving goals, involving weak-will, and lower organization skills. • Extraversion: This factor addresses an array of sociable styles. High scores are associated to a preference for larger groups, being talkative and active, engaging with people, talking assertively, adopting optimistic and cheerful postures. An introvert is not unfriendly but reserved, this person would prefer to be independent rather than following the flock of people, and would keep an even pace as opposed to being slow. • Agreeableness: This factor gauges the altruistic tendency of people. A high score is related to empathy, to being helpful to others and expecting that others will be helpful as well, and to easily development of trust, whereas a low score is associated to competition rather than helpfulness, to being suspicious, and to the tendency of prioritising one’s intentions. • Neuroticism: The Neuroticism factor covers emotional stability. A person with a high score in this factor is prone to experience negative states such as stress, fear, guilt, anger, shame, aversion, and depression. 37 Neuroticism Extraversion Openness To Experience Anxiety Friendliness Imagination Anger Gregariousness Artistic Interests Depression Assertiveness Emotionality Self-Consciousness Activity Level Adventurousness Immoderation Excitement-Seeking Intellect Vulnerability Cheerfulness Liberalism Agreeableness Conscientiousness Trust Self-Efficacy Morality Orderliness Altruism Dutifulness Cooperation Achievement-Striving Modesty Self-Discipline Sympathy Cautiousness Table 11: IPIP personality facets for the big five traits. Whereas low scores can be interpreted as a relaxed person who has a stable temper and can maintain this attitude when coping tense situations. 6.2.2 FFM Facets Each trait is divided into six facets, these facets reflect parts of the traits that they represent. In our research we try to narrow down any effect that we find on a trait. To see if the behaviour that is tied to the effect can be explained using one of the facets. The facets are all defined using a single word which and very straightforward in their interpretation. For every trait we display the IPIP NEO-PI-R facets in table 11. 6.3 Assumptions and Hypotheses In this section we will sum up the most relevant assumptions that have helped shape this research, after stating the assumptions we give our hypothesis for the data analysis based on the assumptions. 38 6.3.1 Game Literacy Game literacy is the knowledge and experience a player has about games. A high game literacy means that a player has learned many tricks, knows conventions of game developers, video game tropes in both game mechanics and flow of a game. Having knowledge about a challenge before it is presented will certainly help in completing that challenge. We therefore assume that players that have many hours played per week and those that explore many different genres of games will have a higher game literacy than those who don’t. Our hypotheses are therefore that the players who play many hours a week will play longer than those that play a few hours a week. Those that have played many games of the action RPG genre will have a better performance than those who have not. 6.3.2 Personality Influence Personality traits and facets can give us insight into the motivations of behaviour, if the found behaviour matches the behaviour that can be extrapolated from a personality trait or facet, then those personality traits or facets could be used to predict certain behaviour in game and possibly the resulting performance or preferences. Openness to experience has already been linked to game literacy in other research, most hardcore players are both introvert and have a high openness to experience1 . In an experiment using a Neverwinter Nights scenario as an alternate way of profiling the player within the FFM model [28], the players which completed the game quickly also showed high scores in Openness to experience. We expect the players with high openness to experience that are interested in games will perform better than those that have low openness to experience but still interested in games. Conscientiousness is the innate drive to micromanage and strive for efficiency, this could indicate that achievements, badges and on screen objectives are likely to have a positive effect with people that score average to high on the conscientious scale. As well as having an inventory or statistics to manage. Recklessness associated with a low Conscientious score could require a more lenient but higher paced gameplay with less elements to manage. As such we hypothesise that a player with a high conscientiousness score will use more items and takes a more careful approach to puzzles and fights. 1 The link between openness to experience and game literacy is likely due to the time that someone has invested in seeking new experiences, if a person has an interest in video games and has a high openness rating then it is likely that the person has played many different games over the years. 39 Extraversion has been linked to more energetic game-play, as well as more involvement in conversations, as seen in [28]. High extraversion also relates to the preference to large social groups which could be simulated by adding bots with which the player should work together with and scaling the difficulty. We hypothesise that more energetic game-play indicates more movement, more exploration, more interaction with NPCs. Agreeableness has also been correlated to the amount of involvement in conversations and courteous behavior in games, as well as the amount of instructions that is gathered during play. We predict that a player with a high agreeableness score will have less trouble finding their way around town and as a result spends less time in the village and finds more items than a player with a low score. Neuroticism as measure of resistance to frustration is a good tool to have when deciding on starting difficulty, difficulty curve and the general amount of challenges to present to the player. The hypothesis is that a player with a low neuroticism score will be less likely to quit after failing a challenge or when a challenge is tedious or arduous. 6.4 Difficulty Preference The requirement for getting into a flow is a balance of skill and challenge [8]. If the challenge is too low or too high then that will cause apathy or frustration respectively and reduce the flow experience. If the player gets into a flow, the sense of time is reduced and the player is more likely to spend more time on a game. Hardcore gamers and casual gamers each have their own level of skill. Balancing the difficulty would therefore be required for players of different skill levels to reach a state of flow. Hardcore gamers would have had more practice and more knowledge on games and as such could handle a higher difficulty level than the casual gamers. Our hypothesis is therefore that a player that performs well will like higher difficulty levels and players with a lower performance will like lower difficulty levels. 7 Method In this section we will describe the methodology used in this paper. This includes introducing all the elements of the experiment, discussing the design, explaining the procedure of the experiments, the data that we collect and how we will process that data. 40 7.1 Method Overview The following flowchart will give an overview of the different parts of this experiment and how they relate to each other. Figure 15: The method overview. Our participants which we have acquired through acquisition methods went to the website and followed the research protocol by following the directions on the website. The data that has been gathered will be analysed based on our design and data categories. In the sections to come we will go over each topic displayed int the method overview (figure 15). The following topics will be discussed: • Acquisition, how we have acquired participants for our research and the amount of participants in each group. • The measurement tools, the tools that we use to gather our data. This includes the demographic questionnaire, the personality test, the game that is played and the post-game questionnaire. • Design, the groupings that are relevant to our experiments. • Procedure, which contains the following topics: – Research protocol, each step of the experiment that the participant goes through. – Measurements, groups of dependent variables that we have measured. 41 – Analysis, our strategy to analyse the data that we gathered. Describing which data groups we will compare with each other with certain tools. 7.2 Participants and acquisition The participants were recruited for this research via personal connections, flyers and personal handouts of flyers. The flyers particularly asked for gamers with some gaming experience. The flyers were handed out and spread around at the University of Amsterdam. In total 25 participants had completed all the instructions. 21 participants were male and 4 were female, the average age was 25.52. All participants have either experience playing games on a desktop, laptop or console. Of these 25 participants, 16 have been presented the adaptable difficulty version and the remaining 9 the static difficulty version, assignment of the versions was done randomly. Figure 16: Demographic data bar plots. 42 7.3 The Demographic questionnaire This questionnaire was used to determine the demographic of the participant, which included the participant’s age, gender, time spent gaming, game genre preference and if they had played The Legend of Zelda: A Link to the Past. This questionnaire is also used to determine whether a participant belongs to the casual or average to hardcore gamer group. A full description of the demographic questionnaire is available in section A of the Appendix. 7.4 The personality test The test is 120 questions large and was designed to capture the NEO-PI-R facets with a high correlation between constructs [16]. The test includes a detailed explanation of how the participant is supposed to interpret the questions and what the scale for each question represents. The questions were interleaved such that there is no question that is followed by a question of the same category. A few examples of the questions that are present in the personality test: • Questions that affect the score of the conscientiousness facet achievement-striving: – Do more than what’s expected of me. – Work hard. – Put little time and effort into my work. – Do just enough work to get by. • Questions that affect the score of the neuroticism facet immoderation: – Go on binges. – Rarely overindulge. – Easily resist temptations. – Am able to control my cravings. • Questions that affect the score of the extraversion facet activity level: – Am always busy. – Am always on the go. – Do a lot in my spare time. – Like to take it easy. 43 Questions are represented in a 5-point Likert scale ranging from very inaccurate (1) to very accurate (5), to get the score for a particular facet or dimension we add together all the scores of the related facet/dimension. Some questions are negatively keyed, which means that the point scale is reversed (5 - 1). A full description of the personality test can be found in section B of the Appendix. 7.5 Dynamic Zelda The game that was played by the participants, we gather data during play and direct mapping of the designated game metrics to log files. We gather behaviour data mainly from the village, fights and level exploration: • Village behaviour data involves how much the participant engaged in conversation and how much preparations the participant had made in the village before heading out to the levels. • Exploration behaviour data involves which areas the player had visited in the village and how much the player went off the main path in the levels. • Fight behaviour data involves movement, usage of items or abilities as well as sword usage. We also gathered performance data from the puzzles and fights, the metrics are mostly focused on how much health the player had lost during the fight or puzzle combined with the time it took to complete it. And lastly we collected level ratings for the experienced difficulty by using a short questionnaire with 5 questions. Figure 17: Screenshot of the in-game questionnaire. 44 A full description of the game is available in section 5 and a full description of the game metrics is available in section C of the Appendix. 7.6 The Post-game questionnaire This questionnaire was used to support the game metrics that were gathered and to explicitly state the preference and the perceived experience of the participant regarding all parts of the game. This includes questions about the overall difficulty of the fights and puzzles and whether the participant also thought that this difficulty fit this type of game. We also asked introspective questions regarding their own in-game behavior within the village, fights and exploration. Almost all the questions that were posed in the post-game questionnaire were of the same nature as the in-game metrics and are only used as support if the in-game metrics are not clear enough. The most important question in the post-game questionnaire is to give the ranking of the preference for each game element (fights, block-pushing, moving floor, maze, exploration, talking to NPCs), ranking the most preferred with 1 and the least preferred with 6. A full description of the Post-game questionnaire is available in section D of the appendix. 7.7 Design The experiment used a 2×1 between-subjects design. The independent variable was the static vs adjustable difficulty. Static vs adjustable gives us an indication if the current execution of the adjustable difficulty adds more value to the game’s experience than a linearly scaling difficulty curve. Casual gamers and average to hardcore gamers are not split because of the existing distinction is unclear and relative and only the participants which clearly fall into one or the other category will be compared later during analysis. The participants are randomly assigned to either the static or the adjustable difficulty group to avoid assignment bias. We sadly cannot avoid any individual variability or environmental bias because of the nature of the experiment (at home when the participant has enough time and want to play). The random assignment might cause an unbalanced group that could open the door for generalization issues. The between subjects design is only to test the static vs adjustable difficulty, when we compare our user profile data with our game metrics we consider both groups equivalent and process them as one group. We 45 assume that the difficulty will have the most effect on performance metrics and we also need data where the difficulty is below or above the player’s level of skill, where a properly working adjustable difficulty setting would deny us that data. 7.8 Procedure In this section we will discuss the procedure of the experiment, the protocol that was followed for each participant during the experiment, the measurements that were made and the analysis strategy that will state what we will test for and what kind of data we will be using during these tests. 7.8.1 Research Protocol During acquisition potential participants were asked if they play a video game once in a while, an explanation of the research followed where the intent behind the research was stated, the steps required were mentioned and that the participants would be able to participate in their own time. Participants were asked to visit a website that explained the details of the experiment. These details included the reasoning behind the experiment, an explanation of the used game engine, the current version of the game, the game’s control schema and the steps required for participation with time estimations for each step. Participants were also informed that they could spread out the participation in the research if necessary, but that participation in one sitting was preferred. A full description of the website can be found in section E of the Appendix. The steps required for participation were visiting the website and completing the following steps: • Fill in the online Demographic questionnaire. • Fill in the online Personality test. • Downloading, installing and playing the game until they didn’t feel like playing or finished the game. • Mailing the logs to a designated e-mail address. • Fill in the online Post-game questionnaire. When a participant had sent all the required logs to the e-mail address and had filled in all questionnaires, the participant then received his personality test results via e-mail. 46 7.8.2 Measurements The dependent variables that were measured for every player are: • Preference regarding parts of the game (Fights / Dark maze / Block-pushing puzzle / Moving-floor puzzle / Talking to characters / Walking around and exploring). • Performance of the player regarding the puzzles (Dark maze / Block-pushing puzzle / Moving-floor puzzle). • Performance and behavior of the player during the fights. • Behavior of the player in the village. • Exploration data for each segment. • The participant’s personality score. 7.8.3 Analysis strategy For our analysis we look for strongly correlated variables using the Spearman Rank-Order Correlation Coefficient. We are not looking for direct cause but primarily for monotonic relationships by which the participants’ preferences, behaviour or performance can be predicted or explained using the personality trait and facet definitions. We will also be comparing distributions using the Kolmogorov–Smirnov test. The following combinations will be used with the above tests: • Personality dimensions and facets correlations with performance, preference and behaviour variables. • Performance correlations with player preference and perceived difficulty. • Comparing casual player preference distribution with non-casual player preference distribution. • Comparing the ratings distribution of the static difficulty and the adaptable difficulty setting. To link personality with preference we will investigate the correlations and try to draw meaningful conclusions from our data given our definitions and assumptions. 47 By comparing ratings distributions of our adaptable difficulty setting and the static linearly scaling difficulty setting we can give an indication of whether or not our difficulty adjustment has made an improvement to our game’s experience. If any interesting relationships between personality and preference arise we can investigate whether the personality trait can be predicted with any of our game metrics and as such provide a meaningful way of profiling a player’s personality through game metrics and consequently predict the preferences. 8 Experiments In this section we will present the results from our experiments that are relevant to any research question or hypothesis that was presented earlier in the paper in the research questions section (1.1) and the assumptions and hypotheses section (6.3). The results are then followed up by a short analysis on the topic of the relevant research question or hypothesis. Experiment 1: The difficulty level of the fights and puzzles is predetermined per level. Experiment 2: The difficulty level for a game element (fight or puzzle) is based on the participant’s performance for that particular game element. For our experiments we asked participants to follow the instructions on a website, these instructions included filling in questionnaires, playing a game and sending the log files after quitting or completing the game. The allotted time requirements were somewhere between an hour and two hours and our instructions were to be followed in a specific order, preferably when the participant had enough time to complete the instructions in one sitting. We could see in the acquired data and participants’ responses that there were still some issues with the game after presenting it to our participants, these issues were usually fixed straight away and the participant could resume playing. This will most likely introduce some noise. Some participants had quit when a crash occurred, some when the game became too difficult, some out of boredom. The break from the instructions meant that some forgot about the instructions after the game and forgot to send any log files or complete the post-game questionnaire, the data from these participants has been left out of the dataset. 48 8.1 Exploration Method Our data was first subjected to the Shapiro-Wilk test on each measured variable. From this data we could see that the majority of the data is skewed in either direction and that we could reject the hypothesis that the data came from a normal distribution. This means that we cannot use any statistical tools that have an assumption of normality. Thus the use of Pearson product-moment correlation coefficient and Principle Component Analysis is not advised. We will instead keep to investigating possible monotonic relationships by using Spearman Rank-Order Correlation Coefficient on the variables that were mentioned in the hypotheses section. We will explore our research questions using Fast Independent Component Analysis (python library: sklearn.decomposition.FastICA with standard settings), where the number of components are approximated by using the number of components that explained 90% of the variance in the output of Principle Component Analysis (python library: matplotlib.mlab.PCA). The only part that is regrettable is that ICA in general is not a deterministic algorithm and that we might not catch all the components or we could get some small artifacts in our results. The FastICA exploration will be done by correlating the resulting components of the FastICA algorithm with the actual data, we can then see which of the components correlate strongly with each other. We take the strongest correlating variables of a component and try to qualitatively give an explanation to the correlation between these selected variables. In most cases found below we will only discuss the interesting components that have strong correlating variables outside their variable group (e.g. strong correlations between personality dimensions or facets are not of interest, only those that correlate with a game metric). But even when the data correlates strongly with the components, the found component parts (e.g. personality and game metric) should also strongly correlate with each other, because this is the part that we are interested in. 8.2 Gamer type results We have hypothesized that the hardcore gamer preference would diverge from the casual gamer preference. To test this we have compared the distributions of preference between participants using the Kolmogorov–Smirnov test, the results can be seen in figure 18. 49 Within our data we define hardcore gamers as followed: the participant spends a considerable chunk of time on games (10+ hours per week) and has a preference for somewhat challenging content (hard difficulty or higher). Casual gamers are defined as having an interest in games, but not wanting to put in time and effort to get really good at a game, with often a preference for simple games. Within our data that is defined as less than 10 hours per week and Easy difficulty or lower. We also have a gray area where we have potential hardcore gamers that enjoy difficult games but don’t have or invest a lot of time to play, or the possibly casual gamer that puts in considerable amounts of time but doesn’t want a challenge. Figure 18: Boxplots of the preference ranking distribution of participants that classify as hardcore, casual or as unknown. Rank 1 is most liked, rank 6 is least liked. Only the maximum and minimum outliers are shown as circles. The green triangles represent the mean. As can be seen in figure 18, the hardcore gamer preference for the moving 50 floor puzzle is ranked better than the moving floor puzzle ranks for the casual gamers, but most likely due to the outlier in the hardcore gamer pool we cannot say for certain that they are strictly different distributions (p = 0.086 two-sided). Variables other than the moving floor puzzle preference have a too high of a p-value to consider the possibility that their distributions are different for hardcore gamers and casual gamers. Though we cannot reject the hypothesis that they are of the same distribution, the reason why the moving floor puzzle ranks worse for the casual gamers is the nature of the puzzle, it requires more finesse with controlling the character than the other game elements, and this is where the hardcore gamers have the advantage. 8.3 Difficulty setting results To investigate if the adaptable setting was an improvement on our static setting we will again use the Kolmogorov–Smirnov test to determine if the adaptable setting distribution is significantly different from the static setting. The boxplots of the two distributions can be seen in figure 19 Figure 19: Boxplots of the average Likert score of the participants on whether they liked the amount of challenge presented for the fights and puzzles, the overall experience of the levels and the rating of the amount of exploration available. The Likert scale ranges from strongly disagree to strongly agree. Only the maximum and minimum outliers are shown as circles. The green triangles represent the mean. 51 Variable Overall experience Fights Puzzles D 0.224 0.125 0.150 p 0.921 0.999 0.999 Table 12: Two sample KS tests between the average Likert score of liking the following: the game elements difficulty for fights and puzzles, the overall experience of the levels and the rating of the amount of exploration available. Likert scores are from the ingame questionnaire. Figure 20: Boxplots of the average Likert score of the participants on whether they found the difficulty too hard for the fights and puzzles and whether the puzzle difficulty fits this type of game. The Likert scale ranges from strongly disagree to strongly agree. Only the maximum and minimum outliers are shown as circles. The green triangles represent the mean. 52 Variable Fights too hard Maze puzzles too hard Moving floor puzzles too hard Block-pushing puzzles too hard Puzzle difficulty is fitting Puzzles too easy D 0.326 0.562 0.138 0.215 0.437 0.152 p 0.484 0.031 0.999 0.920 0.160 0.997 Table 13: Two sample KS tests between the average Likert score of find the following elements too hard: The difficulty. Likert scores are from the postgame questionnaire 8.4 Personality results In figure 21 and 22 we can see the range of the measured personality dimensions of our participants. We can see that our population has a skewedness towards the higher ends for all of the dimensions except neuroticism. The skewedness could be an indication of the kind of persons that would be more likely to participate in lengthy research. This could have had an influence on our dataset, given that extremes in personality are also more extreme in their actions, which means that we do not have participants that are exceptionally competitive or conservative in their experiences, nor do we have that many reckless persons. But none the less we will try to find meaningful relations within our given dataset. Figure 21: Boxplot of the measured personality dimension scores. Green triangles represent the means. 53 Figure 22: Boxplots of the measured personality facet scores. Green triangles represent the means. 54 8.5 FastICA and Spearman’s rho exploration results To find support or arguments against our hypotheses we will look at the FastICA results and see if any of our hypotheses match a found correlation. In our FastICA exploration we will use the most generic of our game metrics, this will cause our correlations to be less diluted and we can report on metrics that could also be found in other games of this genre. Some of the components that were found have a very small fraction attributed to one of the groups (Personality scores or game metric/element rank), this most likely indicates an artifact which only indicates correlation within a group and should be disregarded. We display all the correlated components parts that have a p-value less than 0.15, considering our data and research objective we should not discard the somewhat weaker correlations without thought. Do not pay a lot of mind to the low modifier values on some of the variables, by using Spearman Rank-Order Correlation Coefficient our correlation is unaffected by low or disproportionate numbers, we should only pay attention to the proportions of each variable within a group because this has influence on the ranking of the data. 8.5.1 Gamer type and personality We first explore how our demographic metrics correlate with our participants’ personality scores, the strongest correlations can be found in table 14. All of the components found are very interesting for our research. We can see that conscientiousness negatively correlates very strongly with all of the hardcore gamer type metrics, which indicates that within out group of participants the conscientious participants were much less into games. We can also see that the strongest correlation within the conscientiousness facets is the negative correlation between achievement-striving, selfdiscipline and many of the hardcore gamer related variables, it is expected that these scores are like this, as hardcore gaming takes up a lot of time the achievement striving facets will be scores low with statements in the personality test such as ”Do just enough work to get by”. The same goes for self-discipline with statements such as ”Waste my time”. As played hours increase so does practice, as such the difficulty preference is also higher. The negative relation between achievement striving and the many different genres played and playing games within favorite genre tells us that low achievers among gamers play more game genres and have developed a 55 favorite genre which is also in line with the hardcore gamer. Personality facets/dimensions (-0.067 · C4:Achievement-striving) +(-0.029 · C5:Self-discipline) (-0.009 · N1:Anxiety) +(-0.032 · N3:Depression) +(-0.021 · N4:Self-consciousness) +(-0.13 · N5:Immoderation) +(-0.018 · N6:Vulnerability) (0.068 · O2:Artistic Interest) +(0.104 · O3:Emotionality) +(-0.075 · O6:Liberalism) Gamer type variables (0.097 · Hours Played) +(0.038 · Difficulty Preference) +(-0.019 · Many different genres) +(0.019 · Within favorite genre) +(0.02 · Action Adventure) (-0.107 · Difficulty Preference) +(-0.055 · Many different genres) +(-0.002 · played Zelda:ALTTP) rho 0.768 p p<0.0005 0.402 0.047 (-0.076 · Within Fav genre) 0.347 0.089 Table 14: FastICA components that weakly correlate the gamer type metrics with the personality facets and dimensions. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. The second strongest correlation is also interesting, it points towards neuroticism as an indicator of difficulty preference as well as the lack of interest in playing different genres. The individual correlations are displayed in table 15. In the table we can see why immoderation is a large part of the component, it correlates strongly with hardcore gamer metrics and playing the action adventure genre in particular. The other neuroticism facets did not correlate significantly with difficulty preference, as such immoderation is likely an expression of being a hardcore gamer where playing for long hours will categorize as binges which brings practice which in turn might increase the difficulty preference due to the amount of practice. The third correlation is interesting but not as as clear as the other correlations in the table. Instead we took a look at the individual correlations between variables of openness to experience and our gamer type variables. Intellect is strongly correlated with difficulty preference, intellect is measured with statements in the personality test such as: ”Have difficulty understanding abstract ideas”. This indicates that participants that have a higher 56 intellect score will most likely have less trouble grasping the conventions used in games and as such will require more challenging material for it to be as rewarding. 57 Facets Neuroticism Extraversion Openness to Experience Agreeableness Conscientiousness O1:Imagination O2:Artistic Interest O3:Emotionality O4:Adventurousness O5:Intellect O6:Liberalism C1:Self-efficacy C2:Orderliness C3:Dutifulness C4:Achievement-striving C5:Self-discipline C6:Cautiousness E1:Friendliness E2:Gregariousness E3:Assertiveness E4:Activity Level E5:Excitement-seeking E6:Cheerfulness A1:Trust A2:Morality A3:Altruism A4:Cooperation A5:Modesty A6:Sympathy N1:Anxiety N2:Anger N3:Depression N4:Self-consciousness N5:Immoderation N6:Vulnerability Hours played Difficulty preference 0.193 -0.378** -0.018 0.169 -0.66**** 0.076 -0.306* -0.064 -0.05 0.15 0.02 -0.429*** -0.404*** -0.098 -0.768**** -0.539**** -0.079 -0.199 -0.318* -0.404*** -0.503*** -0.2 -0.134 0.234 0.075 0.126 -0.145 0.149 0.071 0.07 0.132 0.069 0.3* 0.386** -0.033 0.213 -0.019 0.155 0.057 -0.442*** 0.192 -0.099 -0.054 -0.055 0.44*** 0.135 -0.213 -0.226 -0.254 -0.45*** -0.509**** -0.202 -0.065 -0.075 -0.046 -0.265 0.118 0.218 0.007 0.008 0.08 0.066 -0.005 -0.021 0.085 0.1 -0.039 0.271 0.474*** 0.148 Many different genres 0.221 -0.291 -0.025 -0.018 -0.448*** 0.178 -0.301* -0.158 -0.08 0.165 0.041 -0.389** -0.338** -0.385** -0.43*** -0.264 -0.279 -0.374** -0.195 -0.17 -0.278 -0.214 0.075 -0.086 -0.097 0.038 -0.028 0.079 0.032 0.108 0.115 0.163 0.233 0.197 0.148 Within favorite genre 0.017 -0.287 0.055 0.144 -0.416*** 0.12 -0.371** -0.188 0.24 0.094 0.182 -0.294 -0.365** -0.163 -0.637**** -0.154 -0.119 -0.387** -0.158 -0.245 -0.182 -0.235 0.04 0.035 0.106 0.079 0.113 0.239 -0.054 -0.078 -0.05 -0.002 0.185 0.112 -0.103 Action Adventure genre 0.316* -0.115 0.149 -0.128 -0.259 0.457*** 0.116 0.113 -0.224 0.34** -0.087 -0.413*** 0.142 -0.461*** -0.246 -0.497*** -0.064 -0.032 -0.075 -0.133 -0.363** 0.066 0.088 -0.116 -0.158 0.09 -0.094 -0.081 0.256 0.24 0.292 0.21 0.163 0.572**** 0.123 Table 15: Moderate to strong correlations between personality facets and the gamer type metrics. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 58 8.5.2 Game literacy and performance In the tables below we have correlated the difficulty reached for puzzles and the predicted fight difficulty for the adaptable difficulty setting. In the adaptable difficulty setting we could properly measure how skilled a participant is by measuring the average difficulty level on which the participant was playing. Both table 16 and 17 state that having played The legend of Zelda: A link to the past together with the difficulty preference are the strongest indicators for performance, after which those who play Action Adventure genre games will have some familiarity with the Moving-floor type puzzles. The fight element’s predicted difficulty is our weakest measurement, because the difficulty level is kept relative to ensure the oscillating flow mechanic works properly. Since each monster has a separate weight and relative difficulty it is also not correct to take the weights as measurements of total difficulty. The predicted difficulty was often very high when the player was playing well and as a result a lot of enemies were spawned. As such it is partly indicative of higher performance but also somewhat noisy since a bad player can get a high predicted fight difficulty as well, but not that easily and not as high as when a lot of enemies spawn. Gamer type metrics (-0.06 · Difficulty Preference) +(-0.065 · Action Adventure) +(-0.207 · played Zelda:ALTTP) (-0.014 · Difficulty Preference) +(0.022 · Many different genres) +(0.112 · Action Adventure) +(0.104 · played Zelda:ALTTP) (0.141 · Many different genres) +(0.102 · Within Fav genre) +(0.068 · Action Adventure) +(0.107 · played Zelda:ALTTP) (0.091 · Action Adventure) Difficulty reached (0.048 · Block-pushing difficulty) (0.084 · Moving floor difficulty) (-0.01 · Predicted fight difficulty) (0.242 · Maze difficulty) rho -0.706 p 0.002 0.723 0.002 -0.576 0.02 0.321 0.225 Table 16: FastICA components that strongly correlate the gamer type metrics with the difficulty reached for the adaptable difficulty setting. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. 59 Game element Hours played Difficulty preference Block-pushing Maze Moving-floor Fights 0.286 0.391* 0.043 0.463** 0.55*** 0.509*** 0.455** 0.198 Many different genres 0.077 0.369 0.136 0.365 Within favorite genre 0.224 0.422* 0.024 0.4* Action Adventure genre 0.413* 0.321 0.544*** 0.164 Played Zelda:ALTTP 0.511*** 0.442** 0.741**** 0.467** Table 17: Moderate to strong correlations between the gamer type metrics with the difficulty reached for the adaptable difficulty setting. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.5.3 Game element preference In this section we use the FastICA algorithm to explore the possible link between the game element preference ranking and the performance metrics and personality dimensions and facets. If necessary we investigate further by using the individual correlations. Game element rank (-0.016 · Maze) (0.051 · Fight) Performance metrics (0.096 · time spent) +(-0.041 · got hurt) +(-0.115 · falls) +(-0.019 · Reached difficulty) (-0.2 · hurt) +(0.066 · lift) +(0.014 · useItem) rho 0.25 p 0.239 0.043 0.837 Table 18: FastICA components that correlate the performance game metrics with the game element ranking. Sokoban metrics: time spent, completed, retries, vfm time (time before the first move), reached difficulty. Maze metrics: got hurt, falls (fell into a pit), time spent, reached difficulty. Moving floor metrics: got hurt, time spent, reached difficulty. Fight metrics: hurt (times player got hurt), lift (lifting a rock or bush to throw), useItem (using an item from the player’s inventory), spin (special attack with the sword), predicted difficulty. The found components for performance can be seen in table 18, all of the p-values are high and as such we can conclude that (relative) performance does not have a link with preference. To further give arguments that performance has no link to preference we also calculated the correlations between 60 the achieved difficulty level and preference ranking in the adaptable setting which can be seen in table 19. Game element Block-pushing Maze Moving floor Fights rho 0.062 0.039 0.168 0.002 p 0.82 0.886 0.534 0.995 Table 19: Correlations between the game element’s preference rank and the game element’s achieved difficulty level for the adaptable difficulty setting. In table 20 we can see the the correlation between the strongest component parts for personality dimensions/facets and game element ranking. We can see that there are some interesting correlations which might indicate that there is a link. The most interesting ones are the ones that could be used to get insight into the player or be used as a predictor for preference. For instance the decreased preference for talking to NPCs with decreasing achievementstriving and increased preference for the moving-floor puzzle. This could be the result that secrets and bonuses in other games are often gained through conversation with NPCs, and that the convention now results in an increased preference. Since these facets also correlate strongly with hardcore gamers another possibility is that the hardcore gamer participants feel comfortable with that kind of information gathering and casual gamers less so. A low score for achievement-striving also indicates a more hardcore gamer type and since the required skill with the controls is higher than the other puzzles. The higher requirement could indicate that participants that did not have this required skill liked it a lot less than participants that could properly complete it without getting their character hurt too much. Another example from the table is the increase in extraversion facets that relates to the decreasing preference for fights, we would expect that a person that is more assertive, active or excitements-seeking would be more attracted to fights, not less. We also see that many strong correlations are present that include agreeableness or its facets, comparing the found component parts to the definition of agreeableness has not given us much insight into the preference other than that if the agreeable participants try to follow up on instructions quickly then they’ll spent less time on talking to NPCs even if they would have liked it if they did, which might cause a change in preference ranking. 61 We further investigated personality and game element ranking with individual correlations, see table 21. In this table we can find many strong correlations between personality dimensions/facets and game element ranking, we will discuss all the correlations that have a p-value of less than 0.05. Just like in table 20 we see that the moving floor and talking to NPCs preference correlates with the agreeabless dimension as well as achievment striving correlate with moving floor and talking to NPCs. Imagination correlates strongly with the preference for exploration, which would fit the description of a daydreamer or someone who likes to get lost in thought. Assertive participants like the dark maze more, or maybe it is more accurate to say that less assertive participants found the dark maze to be disheartening. Trust correlates strongly with the moving floor puzzle, one explanation could be that if the trust facet would have captured the participant’s inclination towards finding patterns and believing in them, since the moving floor puzzles variations all have a distinct pattern, making it easier and more properly solvable by someone that has the pattern down, otherwise such a strong correlation with such a social facet makes little sense. Modesty correlates strongly with the block-pushing puzzle preference. Again a primarily social facet correlates with a puzzle preference, one explanation could be that a person who thinks highly of themselves finds extra enjoyment from the eureka sensation that these kinds of puzzles bring compared to other participants that might not feel the need to strengthen their own belief that they are better than others. Sympathy correlates strongly with the dark maze preference. Another social facet that correlates with a puzzle type. Sympathy is a personality trait that speaks of emotionality when another person or being is in trouble or in distress. Whether the emotionality is a rewarding sensation or not is unclear, but if it is then that emotionality might also be triggered by dark maze setting. Other than that the description of the facet nor the test statements on which the facet is based bring insight into this strong correlation. Anger correlates strongly with the block-pushing puzzle. An explanation could be that the more angry a person becomes when not being able to solve a block-pushing puzzle the more contrast there is in their emotions when they do get that eureka sensation, which they experience more strongly then. Another explanation is that the participants that are easily frustrated quit sooner into the game and never get to a hard enough block-pushing puzzle to cause them to get irritated, causing it to rise in preference by the decrease 62 in preference of other elements. 63 Personality facets/dimensions (-0.002 · C4:Achievement-striving) (-0.152 · A2:Morality) +(-0.118 · A4:Cooperation) (-0.102 · A3:Altruism) +(-0.094 · A6:Sympathy) (0.032 · A1:Trust) +(-0.042 · A4:Cooperation) +(-0.068 · A5:Modesty) +(0.009 · A6:Sympathy) (-0.026 · Agreeableness) (-0.058 · Agreeableness) (-0.086 · E3:Assertiveness) +(-0.061 · E5:Excitement-seeking) +(0.08 · E6:Cheerfulness) (-0.01 · N1:Anxiety) +(-0.016 · N2:Anger) +(-0.01 · N3:Depression) +(-0.022 · N6:Vulnerability) (-0.005 · Openness to Experience) +(-0.004 · Agreeableness) (0.021 · Neuroticism) +(-0.025 · Extraversion) +(0.008 · Conscientiousness) (-0.039 · C1:Self-efficacy) +(-0.123 · C4:Achievement-striving) +(-0.054 · C5:Self-discipline) (0.139 · A1:Trust) (-0.064 · E1:Friendliness) +(-0.041 · E2:Gregariousness) +(0.023 · E4:Activity Level) +(-0.046 · E5:Excitement-seeking) +(-0.04 · E6:Cheerfulness) (0.018 · O1:Imagination) +(0.086 · O2:Artistic Interest) +(0.092 · O3:Emotionality) Game element rank (0.031 · Moving floor) +(-0.106 · Talking to NPCs) (0.111 · Talking to NPCs) rho -0.485 p 0.014 -0.478 0.016 (0.031 · Dark maze) 0.466 0.019 (-0.087 · Fights) +(0.038 · Block-pushing) 0.442 0.027 (0.12 · Moving floor) (0.072 · Fights) +(-0.089 · Talking to NPCs) (-0.093 · Fights) 0.43 0.424 0.032 0.035 0.393 0.052 (0.093 · Block-pushing) 0.379 0.061 (-0.099 · Exploring) 0.365 0.073 (-0.094 · Block-pushing) 0.351 0.085 (0.018 · Talking to NPCs) 0.332 0.105 (0.134 · Fights) (-0.063 · Block-pushing) -0.328 0.311 0.109 0.13 (0.101 · Dark maze) -0.307 0.135 Table 20: FastICA components that strongly correlate preference ranking with the personality scores. A lower rank means more preferred. 64 Personality dimensions/facets Neuroticism Extraversion Openness to Experience Agreeableness Conscientiousness O1:Imagination O2:Artistic Interest O3:Emotionality O4:Adventurousness O5:Intellect O6:Liberalism C1:Self-efficacy C2:Orderliness C3:Dutifulness C4:Achievement-striving C5:Self-discipline C6:Cautiousness E1:Friendliness E2:Gregariousness E3:Assertiveness E4:Activity Level E5:Excitement-seeking E6:Cheerfulness A1:Trust A2:Morality A3:Altruism A4:Cooperation A5:Modesty A6:Sympathy N1:Anxiety N2:Anger N3:Depression N4:Self-consciousness N5:Immoderation N6:Vulnerability Fights Block-pushing Dark maze Moving floor 0.015 0.195 -0.048 -0.19 -0.071 -0.074 -0.008 0.014 0.096 -0.069 0.003 -0.067 -0.036 -0.31* 0.123 0.077 -0.107 -0.032 0.158 0.143 0.323* 0.287 -0.099 -0.328* -0.153 -0.117 0.117 -0.005 -0.141 0.117 -0.024 0.047 -0.006 -0.103 0.074 -0.297* 0.331* -0.116 0.024 0.305* -0.163 0.223 -0.107 -0.107 0.045 -0.305* 0.322* 0.127 0.193 0.229 0.131 0.108 0.33* 0.383** 0.303* 0.155 0.229 0.148 0.348** -0.125 0.054 -0.231 -0.439*** 0.322* -0.21 -0.477*** -0.318* -0.003 -0.093 -0.312* 0.138 -0.146 -0.281 -0.24 -0.164 -0.244 -0.242 -0.249 -0.283 -0.097 0.275 -0.343** -0.005 -0.024 0.034 -0.053 -0.132 0.023 -0.237 -0.449*** 0.043 0.054 -0.002 -0.075 -0.143 -0.372** -0.031 0.225 -0.502*** 0.048 0.315* -0.03 0.006 0.18 0.271 0.268 -0.156 -0.11 -0.43*** 0.008 0.015 -0.003 0.03 -0.235 -0.254 0.198 0.03 -0.164 -0.174 0.403*** 0.139 -0.148 -0.309* -0.274 -0.046 0.153 -0.263 -0.066 -0.448*** -0.369** -0.229 -0.044 -0.129 -0.252 0.332* 0.357** 0.167 0.051 -0.222 0.393** Talking to NPCs -0.001 -0.203 0.183 0.401*** -0.213 0.068 -0.015 0.108 0.234 0.04 -0.042 -0.068 -0.104 -0.084 -0.459*** -0.064 -0.107 -0.13 -0.151 0.13 -0.359** -0.284 -0.182 0.018 0.39** 0.277 0.312* 0.203 0.143 -0.072 -0.051 0.127 -0.093 -0.027 -0.024 Table 21: Correlations between the game element’s preference rank and personality scores for dimensions and facets. A lower rank means more preferred. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 65 Exploring -0.034 -0.068 0.371** 0.277 0.103 0.403*** 0.031 0.293 0.33* 0.284 -0.172 0.138 0.168 0.138 -0.249 -0.203 0.343** 0.003 0.068 0.061 -0.29 -0.113 0.036 0.198 0.311* 0.331* -0.05 0.085 0.291 -0.096 0.016 0.143 -0.048 0.181 -0.282 Game element Fights Block-pushing Dark maze Moving floor Talking to NPCs Exploring Hours played Difficulty preference -0.176 -0.112 -0.014 -0.425*** 0.329* 0.267 -0.023 -0.024 0.127 -0.262 0.175 -0.084 Many different genres -0.015 -0.291 0.051 -0.221 0.458*** 0.028 Within favorite genre 0.017 -0.38** -0.094 -0.239 0.501*** 0.207 Action Adventure genre 0.042 0.084 -0.124 -0.252 -0 0.205 Played Zelda:ALTTP Table 22: Correlations between the the gamer type metrics and the game element’s preference rank. A lower rank means more preferred. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 In table 22 we can see that there is a correlation between gamer type metrics and preference, but that this is unrelated to the actual performance. The block-pushing puzzles were a frequent occurring type of puzzle in The Legend of Zelda: A link to the past. It makes it likely that nostalgia then influences the preference of the block-pushing puzzle. Participants that play games for many hours a week tend to have an increased preference for the moving floor puzzle. The moving floor puzzle likely appeals to participants that have a finer control over the character. Participants that play games often have a decreased preference for talking to NPCs, this does not mean that they talk to NPCs less, but it could also mean that they tend to skip a lot of dialog. Participants that play a lot of games often know that most information attained from the NPCs is not important for the game, only the act of talking to them because it is often the trigger for other events. 66 0.115 -0.339** 0.17 0.174 0.138 -0.103 8.5.4 NPC and conversation interaction Personality facets/dimensions (0.026 · E1:Friendliness) +(0.006 · E2:Gregariousness) +(0.049 · E3:Assertiveness) +(0.001 · E4:Activity Level) (0.068 · A4:Cooperation) +(0.085 · A5:Modesty) (0.028 · A2:Morality) +(0.006 · A3:Altruism) +(0.028 · A5:Modesty) +(0.006 · A6:Sympathy) (-0.014 · N1:Anxiety) +(-0.002 · N2:Anger) +(-0.028 · N4:Self-consciousness) +(-0.024 · N6:Vulnerability) (0.057 · E4:Activity Level) +(-0.075 · E5:Excitement-seeking) Game metric (0.006 · AreasVisited) rho 0.443 p 0.03 (-0.046 · npcs talked to) +(-0.106 · AreasVisited) (0.028 · npcs talked to) +(0.008 · Extra options taken) +(0.006 · AreasVisited) 0.509 0.011 -0.419 0.041 (0.01 · npcs talked to) +(0.011 · AreasVisited) 0.391 0.059 (-0.025 · Extra options taken) 0.335 0.11 Table 23: FastICA components that strongly correlate the village game metrics for conversations with the personality scores. Conversation metrics: NPCs talked to, Extra options taken (conversation options taken minus NPCs talked to). AreasVisited is a combined metric, the sum of all boolean values of visited village areas. In table 23 we can see a similar effect regarding Agreeableness and the preference for talking to NPCs, the cooperation facet is a common factor in both. One possible explanation is that participants that score high in the cooperation facet want to start the quest as soon as possible, given that the entire premise and directions were given at the very start. With regards to extraversion we have predicted that the play-style would be more active, have more interactions with NPCs as well as more exploration, the correlation found in table 23 seems to support the exploration part. We can also see that a lower score for the neuroticism facets selfconsciousness, vulnerability and anxiety also relates to the amount of NPCs talked to and the amount of areas visited. An explanation could be that participants with high neuroticism scores project their social anxieties onto the characters in the game, causing the participants to avoid talking to NPCs. In table 24 we can see that participants that play a lot of Action Adventure 67 genre games talk to a lot of NPCs and explore the other conversation options that are available. This is to be expected as it is a convention that bonuses or secrets can be found in Action Adventure games through conversation. Game metric Hours played Difficulty preference npcs talked to Extra options taken AreasVisited -0.069 0.303 -0.13 0.009 0.204 -0.016 Many different genres 0.197 0.024 0.165 Within favorite genre 0.141 0.119 -0.079 Action Adventure genre 0.515*** 0.686**** 0.296 Played Zelda:ALTTP -0.105 0.025 -0.225 Table 24: Correlations between the the gamer type metrics and the village game metrics for conversations. Conversation metrics: NPCs talked to, Extra options taken (conversation options taken minus NPCs talked to). AreasVisited is a combined metric, the sum of all boolean values of visited village areas. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 Personality dimension/facets Extraversion E1:Friendliness E2:Gregariousness E3:Assertiveness E4:Activity Level E5:Excitement-seeking E6:Cheerfulness NPCs talked to 0.342* 0.22 0.372** 0.252 0.082 0.133 0.491*** Extra options taken 0.2 0.201 0.134 0.038 -0.091 0.303* 0.217 AreasVisited 0.33* 0.325* 0.305* 0.385** 0.143 0.116 0.417*** Table 25: Correlations between the the extraversion dimension/facet scores and the village game metrics for conversations. Conversation metrics: NPCs talked to, Extra options taken (conversation options taken minus NPCs talked to). AreasVisited is a combined metric, the sum of all boolean values of visited village areas. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.5.5 Village preparation In the game the player could prepare for the journey by buying specific items from the shops, the apples which each heal a heart on use and the bottle which can be found in the bush patch left of the player’s house and which 68 can be filled at the witch’s shop which buys you a diluted potion which also heals a single heart. Personality facets/dimensions (0.023 · N1:Anxiety) +(0.034 · N2:Anger) +(0.012 · N3:Depression) +(0.029 · N6:Vulnerability) Game metric (-0.087 · apples) +(-0.028 · BottleStats) rho 0.39 p 0.059 Table 26: FastICA components that strongly correlate the village game metrics about preparation before heading out with the personality scores. Preperation metrics: apples, BottleStats (0: no bottle, 1: got empty bottle, 2: filled bottle). In table 26 there is a moderately strong correlation between neuroticism facets and preparation metrics. An explanation could be that participants that score lower on neuroticism facets are more relaxed while playing and think more about planning ahead than if they were to be somewhat more emotional. But a more likely case is that the personality plays a much smaller part than the conventions within action adventure games that preparation is often useful or even vital, this explanation is supported by the correlation of the component parts in table 27 and that our game metrics pointed out that 11 out of 25 did not even find the empty bottle and 10 out of 25 did not buy any apples of which 7 participants did not even visit the plaza where the apples were sold, which undermines the personality aspect if not every player has the convention of preparation. Gamer type metrics (0.007 · Many different genres) +(0.036 · Within Fav genre) +(0.04 · Action Adventure) Game metrics (0.109 · apples) +(0.079 · BottleStats) rho 0.586 p 0.003 Table 27: FastICA component that strongly correlates the gamer type metrics with the village preparation metrics. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. Preparation metrics: apples, BottleStats (0: no bottle, 1: got empty bottle, 2: filled bottle). 69 Personality dimension/facets Agreeableness A1:Trust A2:Morality A3:Altruism A4:Cooperation A5:Modesty A6:Sympathy apples -0.12 0.061 -0.145 -0.028 -0.007 -0.164 0.013 BottleStats 0.139 0.374** 0.087 0.241 -0.129 -0.031 0.132 Time spent -0.187 0.121 -0.216 0.065 -0.325* -0.145 0.069 Table 28: Correlations between the the agreeableness dimensions/facets scores and the village preparation game metrics. Preparation metrics: apples, BottleStats (0: no bottle, 1: got empty bottle, 2: filled bottle). *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.5.6 Fights In this section we investigate the fight variables that have a form of choice or strategy involved. Usage of items or lifting an item means keeping yourself alive by finding resources or by using apples, it can also mean the use of items and lift that the player has uses bombs, throwable props or other items to soften up the enemies. The use of the spin attack is useful where many enemies are afoot, but when improperly timed the enemy will hurt the player before the attack is fully charged. Our hypothesis was that a high conscientiousness score would lead to a more careful approach, but a lower extraversion score might be a better indicator of using a more ”steady” approach. An argument for the low extraversion can be made if high extraversion would be related to being heavily influenced by the environment, as this would reduce any effect that conscientiousness would have on the planning capability during a fight. It should be noted that our conscientiousness data is skewed and that we do not know what kind of impact lower scores could have had on the components. 70 Personality facets/dimensions (0.038 · E1:Friendliness) +(-0.001 · E2:Gregariousness) +(0.032 · E3:Assertiveness) +(0.033 · E4:Activity Level) (0.05 · E1:Friendliness) +(-0.047 · E5:Excitement-seeking) (0.075 · Neuroticism) +(-0.05 · Extraversion) +(-0.105 · Conscientiousness) (0.038 · E2:Gregariousness) +(0.066 · E3:Assertiveness) +(-0.108 · E5:Excitement-seeking) +(0.124 · E6:Cheerfulness) (-0.031 · C1:Self-efficacy) +(-0.015 · C2:Orderliness) +(-0.033 · C4:Achievement-striving) +(-0.013 · C5:Self-discipline) (0.06 · O2:Artistic Interest) +(-0.005 · O3:Emotionality) +(0.031 · O5:Intellect) Game metric (-0.023 · itemUse) rho 0.463 p 0.02 (-0.174 · spin) 0.433 0.03 (-0.048 · spin) -0.466 0.019 (-0.08 · lift) 0.362 0.075 (0.009 · spin) +(0.014 · lift) +(0.011 · useItem) 0.338 0.098 (-0.004 · spin) +(-0.008 · lift) +(-0.015 · useItem) 0.329 0.108 Table 29: FastICA components that strongly correlate the fight game metrics with the personality scores. Fight metrics: lift (lifting a rock or bush to throw), useItem (using an item from the player’s inventory), spin (special attack with the sword). Although with a weaker correlation, the participants which played games more often and have a higher difficulty preference were more likely to use the tools at their disposal. This is in line with our definition of a hardcore gamer. 71 Gamer type metrics (-0.065 · Hours Played) +(-0.05 · Difficulty Preference) +(-0.016 · Within Fav genre) Game metric (0.109 · spin) +(0.048 · lift) +(0.039 · useItem) rho -0.345 p 0.091 Table 30: FastICA components that moderately correlate the gamer type metrics with the fight game metrics. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. Fight metrics: lift (lifting a rock or bush to throw), useItem (using an item from the player’s inventory), spin (special attack with the sword). 8.5.7 Block pushing puzzle Looking at table 31 we can see a large effect of the openness to experience on the performance metrics of the block pushing puzzle. Again we expected to see conscientiousness to appear here as planning is key in solving these kinds of puzzles, although the puzzle could also be reset an infinite amount of times, which undermines the planning aspect. Openness to experience has been linked to hardcore gamers [5], but the FastICA exploration did not come up with any strong correlations regarding gamer type metrics and the block-pushing metrics. A reason for these results could be that the metrics that were recorded do not have a clear strategy or behavioural pattern behind them, as such we might not have the right measurements to find any meaningful relations between these metrics and personality scores and the internal workings that they represent. 72 Personality facets/dimensions (-0.036 · Openness to Experience) +(-0.05 · Agreeableness) (0.056 · A2:Morality) +(0.083 · A3:Altruism) +(0.046 · A4:Cooperation) +(0.038 · A5:Modesty) +(0.044 · A6:Sympathy) (0.003 · N1:Anxiety) +(0.012 · N3:Depression) +(0.095 · N4:Self-consciousness) +(0.079 · N5:Immoderation) Game metric (-0.09 · time spent) +(-0.036 · retries) +(-0.062 · average vfm time) (0.044 · time spent) +(0.059 · retries) rho 0.401 p 0.052 0.365 0.079 (-0.079 · time spent) +(0.007 · retries) +(-0.062 · average vfm time) 0.356 0.088 Table 31: FastICA components that strongly correlate the block-pushing game metrics with the personality scores. Block-pushing metrics: time spent, completed, retries, vfm time. 8.5.8 Moving floor puzzle In table 32 we see again that a facet that is associated with the hardcore gamer type is associated with performance. This was to be expected, an experienced player has better control over the character which means better performance on the moving floor puzzle. Cooperation also correlates strongly with the performance metrics, but this is not one associated with the hardcore gamer metrics. Our less cooperative participants performed better at the moving floor puzzle. This could just be an artifact or it has to do with an underlying element of cooperation. Sadly the definition and the test statements have not given any insight. The correlation with neuroticism, extraversion and conscientiousness is most likely the same one as in table 15 that correlates the same dimensions with ”Played Zelda:ALTTP”. Participants that have not played the game before are at a disadvantage and do not have a feel for the controls yet. For those who have played it and got far in the game, this type of puzzle should be familiar. The correlation between activity level and the performance metrics looks to be an expression of the gamer type metrics ”Hours played” and the resulting lack of feel for the controls. 73 Personality facets/dimensions (-0.012 · C5:Self-discipline) (0.002 · A4:Cooperation) (0.076 · O1:Imagination) +(0.045 · O3:Emotionality) +(-0.072 · O4:Adventurousness) +(0.051 · O5:Intellect) +(-0.099 · O6:Liberalism) (0.109 · Neuroticism) +(-0.076 · Extraversion) +(-0.038 · Conscientiousness) (0.03 · E4:Activity Level) Game metric (-0.11 · time spent) +(-0.1 · got hurt) (-0.1 · time spent) +(-0.104 · got hurt) (0.018 · time spent) (0.002 · got hurt) (0.1 · time spent) +(0.091 · got hurt) rho 0.638 p 0.001 -0.515 0.01 -0.448 0.028 -0.407 0.048 0.382 0.065 Table 32: FastICA components that strongly correlate the moving floor game metrics with the personality scores. Moving floor metrics: got hurt, time spent. Game metric time spent got hurt Hours played Difficulty preference -0.29 -0.417*** -0.293 -0.272 Many different genres 0.093 -0.185 Within favorite genre 0.129 -0.2 Action Adventure genre -0.414*** -0.248 Played Zelda:ALTTP Table 33: Correlations between the moving floor game metrics and the gamer type metrics. Moving floor metrics: got hurt, time spent. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.5.9 Maze puzzle Comparing tables 34 and 35 we can see that gamer type metrics correlate much stronger with the performance metrics than the personality scores, the personality facets found in the components are also related to gamer type metrics. We can see that the hurt and falls increase with the hardcore gamer metrics. This can be easily explained as the difficulty in the adaptable 74 0.03 -0.297 setting only goes up when the player finishes within a certain time frame, if the player struggles somewhat with the controls then time is wasted and the difficulty doesn’t increase or doesn’t increase as much. We can see that the more hardcore gamer types perform better in terms of time. As such the players that got further were mostly the hardcore gamer types and had to deal with more hazards including the pitfalls, which in turn increases the amount the character got hurt and the amount of falls. Personality facets/dimensions (-0.06 · E4:Activity Level) (0.002 · C1:Self-efficacy) +(0.081 · C4:Achievement-striving) +(0.025 · C5:Self-discipline) (-0.086 · A1:Trust) +(-0.051 · A2:Morality) +(-0.051 · A3:Altruism) +(-0.054 · A6:Sympathy) Game metric (-0.092 · time spent) +(0.106 · falls) (0.04 · time spent) +(-0.101 · got hurt) +(-0.042 · falls) (-0.043 · got hurt) +(0.047 · falls) rho 0.366 p 0.079 0.324 0.122 0.32 0.128 Table 34: FastICA components that strongly correlate the maze game metrics with the personality scores. Maze metrics: got hurt, falls, time spent. Game metric time spent got hurt falls Hours played Difficulty preference -0.335* 0.611**** 0.449*** -0.714**** 0.355** 0.342* Many different genres -0.534**** 0.328* 0.405*** Within favorite genre -0.424*** 0.382** 0.214 Action Adventure genre 0.1 0.427*** 0.45*** Played Zelda:ALTTP Table 35: Correlations between the maze game metrics and the gamer type metrics. Maze metrics: got hurt, falls, time spent. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.5.10 In-game exploration In table 36 we can see an increase in exploration and total time spent on the game with the increase of the openness facets. 75 -0.344** 0.087 0.358** Imagination and artistic interest were both found to correlate with the ”Action Adventure genre” and ”played Zelda:ALTTP” gamer metrics. This could indicate that the experience or interest toward these type of games is heightened by both of those facets. We have also investigated the individual correlations of the personality scores and again no strong correlation was found. Investigating the individual correlations with gamer type metrics did give us results as can be seen in table 37. Looking at the individual correlations we can see that playing action adventure genres strongly correlates with the total time spent on the levels, the amount of exploration and the resulting rewards retrieved. The many different genres as well as the ”played Zelda:ALTTP” metrics had a role in the amount of time spent on the game. This means that the amount of time the participants spend on the game, and the amount of optional content the participants want to partake in is mostly influenced by their game history, learned conventions and perhaps nostalgic feelings towards those games. Another interesting correlation is the hardcore gamer type metrics with the average percentage of time spent on the optional path. From our data we can see that this is likely due to the players that get far, will eventually lose interest in exploration and deviation from the main path, resulting in a lower percentage of time spent on the optional path. Personality dimensions/facets (-0.032 · O1:Imagination) +(-0.031 · O2:Artistic Interest) +(0.013 · O3:Emotionality) +(0.006 · O5:Intellect) Exploration metrics (-0.036 · Total time Spent) +(-0.036 · Total unique rooms visited) +(-0.019 · Average percentage of unique rooms visited) +(-0.041 · Average rewards retrieved percentage) Table 36: FastICA component that strongly correlates the personality scores with the exploration metrics. Exploration metrics: Time Spent, Unique rooms, time per unique room, average reward retrieved percentage, average time spent optional percentage 76 rho 0.455 p 0.022 Game metric Hours played Difficulty preference Within favorite genre 0.311* 0.232 0.184 -0.055 Action Adventure genre 0.615**** 0.514**** 0.476*** 0.174 Played Zelda:ALTTP 0.281 0.15 0.045 -0.138 Many different genres 0.43*** 0.278 0.186 0.058 Total time Spent Total unique rooms visited time/unique room Average percentage of unique rooms visited Rewards retrieved percentage Average percentage of time spent on optional path 0.197 0.036 -0.05 -0.127 0.063 0.3* 0.127 0.073 0.526**** 0.284 -0.363** -0.477*** -0.278 -0.307* -0.158 -0.436*** Table 37: Correlations between the exploration game metrics and the gamer type metrics. Exploration metrics: Time Spent, Unique rooms, time per unique room, rewards retrieved percentage, average time spent optional percentage. Gamer type metrics: Hours Played, Difficulty Preference, Many different genres, Within Fav genre, Action Adventure, played Zelda:ALTTP. *: p<0.15, **: p<0.1, ***: p<0.05, ****: p<0.01 8.6 Summary of Findings • Distribution comparisons of hardcore and casual participants show that we cannot reject that they are drawn from the same underlying distribution. • The skewedness in the personality dimension/facets distributions could be an indication of the kinds of persons that are likely to participate in lengthy research (1+ hours). • Conscientious participants were much less into games. • Low achievers (achievment-striving, conscientiousness facet) among gamers play more game genres and have developed a favorite genre. • Neuroticism could be used as an indicator of difficulty preference and lack of interest in playing different genres. • A high immoderation (neuroticism facet) score is an indicator of being a hardcore gamer that binges by playing games for long hours. • A high intellect (Openness to experience facet) score indicates less trouble grasping conventions in games. 77 0.492*** 0.381** 0.28 0.19 • Having played ”The Legend of Zelda: A link to the past” before and having a high difficulty preference are the strongest indicators for performance. • Game element preference correlations: – Performance metrics do not correlate with game element preference ranking. – Achievement-striving correlates positively with the preference for talking to NPCs and the moving floor puzzle, likely is that hardcore gamers like conversations less than challenges that involve controls. – Increase in extraversion facets decreases the preference for fights. – Many strong correlations are present that include agreeableness or its facets, using the definitions has not given us insight into the relation to preference. Indication of one or more latent variables. – Openness to experience facet imagination correlates strongly with the preference for exploration. – Extraversion facet assertiveness correlates with the preference for the dark maze. – Agreeableness facet trust correlates strongly with preference for the moving floor puzzle. – Agreeableness facet modesty correlates strongly with the blockpushing puzzle preference. – Agreeableness facet sympathy correlates strongly with the dark maze preference. – Agreeableness facet anger correlates strongly with the blockpushing puzzle. – ”Played Zelda:ALTTP” correlates with the block-pushing puzzle preference, which might be a nostalgia effect. – The moving floor puzzle preference correlates with hours played. – ”Many different genres played” and ”Play a lot within favorite genre” metrics correlate negatively with the preference for talking to NPCs, likely due to the convention that conversations with NPCs are often not that important, only the act of talking to them which can trigger events. 78 • Agreeableness facet cooperation might be an indication of the tendency to follow instructions and as such leave the village as soon as possible, resulting in less NPCs talked to and less preparation. • Participants with high neuroticism scores might project their own anxieties onto the characters in the game, resulting in less NPCs talked to. • Participants that play a lot of action adventure genre games are likely more familiar with the convention of bonuses and secrets that are unlocked through conversation, as such talk more to NPCs. • Participants which played games more often and have a higher difficulty preference were more likely to use the tools at their disposal. • Total time spent on the game and the amount of exploration correlates with the openness facets. • The ”play action adventure genre a lot” and ”played Zelda:ALTTP” metrics correlated with the openness facets imagination and artistic interest. This could indicate that the experience or interest toward these type of games is heightened by both of those facets. • Players that get far will eventually lose interest in exploration and deviation from the main path, resulting in a lower percentage of time spent on the optional path. 8.7 Discussion of the Results In this section we address each hypothesis and research question with our found results. 8.7.1 Discussing research questions In this section we will discuss the relevant data that we have found per research question and to present an answer to the research question based on that data. RQ 1: Can we link performance to preference? In the game element preference section in tables 16 and 15 we can see that the relative performance and reached difficulty does not correlate significantly 79 with the preference ranks, as such we can rule out performance as a link to preference. RQ 2: Can we link personality to preference? In tables 20 and 21 we see many different preference correlations that are significant, but in some of these cases it is indirectly measuring latent variables that we already know of, one such latent variable, the hardcore gamer type, can be seen correlating significantly with achievement-striving. The agreeableness facets are all measured with social statements in the test and they seem to capture something else than the gamer type or the social aspect because the agreeableness facets do not correlate with gamer type metrics, but do correlate with performance metrics (all puzzles) and village metrics such as the NPCs talked to, the amount of exploration in the village. The neuroticism facets correlate with preference, but just like the agreeableness facets they do not correlate with gamer type metrics but they do correlate with village metrics (NPCs talked to, village exploration and preparation) and performance metrics (block-pushing and moving floor puzzle). The extraversion facets also correlate with preference but less significantly, it does correlate with village metrics and some performance metrics but is not useful for determining preference. The link between personality and preference is present within our data, but the correlations are most likely caused by latent variables that are expressed through the personality facets. RQ 3: Can we link difficulty preference and game knowledge to preference? In the game element preference section in table 22 we can see that difficulty preference does not correlate significantly with any of the preferences. As such we will rule out difficulty preference as a link to game element preference. Hours played correlated significantly with the moving floor puzzle, and we expect this to be the case because of the finer control required for the puzzle and the amount of practice someone has from playing games for so many hours, considering that the preference did not correlate with performance means that not having the finer control did not influence the preference in a bad way. 80 The demographic metrics ”Many different genres played” and ”Play a lot within my favorite genre” have a significant negative correlation with the Talking to NPCs preference rank, it is speculated that this is because of the convention in games that conversation is rarely important and most of it can be skipped. To further support this, in table 22 the amount of NPCs talked to did not correlate significantly with either ”Many different genres played” or ”Play a lot within my favorite genre” metrics as such the preference does not express itself in actually engaging with the NPCs, but more the overall liking of the engagement with the NPCs. The knowledge about Zelda:ALTTP seemed to have influenced the preference towards block-pushing but this result was not significant. We suspect nostalgic feelings to have an influence. RQ 4: Should a game generation algorithm also focus on Dynamic difficulty adjustment? In the difficulty setting results section we had performed the KolmogorovSmirnov test to determine if the distributions were significantly different from each other. The test showed that we cannot reject the hypothesis that the data is drawn from the same distribution and the proportion of hardcore and casual gamers per group is about the same (4 hardcore and 2 casual in static, 6 hardcore and 4 casual in adaptable). Therefore we conclude that our version of adaptable difficulty was not experienced significantly different from the static linearly increasing difficulty. The significant distribution difference for Mazes is caused by a the difficulty adjustment settings, which caused the maze to stay too easy for the adaptable difficulty setting. Our stance is that Dynamic difficulty adjustment should be in a game if it is appropriate for the game itself, having a bad parametrized DDA system is likely no different and possibly worse than creating static scenarios from which to randomly select. RQ 5: Can we create a game that enables us to gather data to test the possibility of these links and the dynamic difficulty adjustment? We have created a game that gathered performance and behavioural metrics as well as ratings for each level via an in-game questionnaire, the game contains many elements which were relevant within our limited scope. The ratings have been used to compare the distributions between static and ad81 aptable difficulty settings. The performance metrics and behavioural metrics have enabled us to explore most of the chosen user profile metrics. The game also makes a clear distinction between elements which creates less noise in our data, the game was received well among our participants. No participant actually disliked the game, but some had points of critique towards the balance of content in the game (exploration / conversations / fights / puzzles) or the results of the content generation algorithms (looked too computer generated). RQ 6: If any links can be found is there a viable player profiling solution among them? Gamer type can be measured through difficulty reached and performance, the gamer type can then be used to estimate preference by assuming the effects of certain gamer type aspects (mastery over controls, conventions such as dialog skipping and bonuses/secrets via conversation). The effect of personality on preference is hard to assume since the underlying metric which we are measuring is unknown, therefore it is harder to apply this to new cases where we have no data. It is more likely that personality scores are not the correct metrics to use to profile players for their preference or their predicted performance in certain game elements. 8.7.2 Discussing personality effect hypotheses Hypothesis: Higher openness to experience results in better performance Only the intellect facet correlates significantly with difficulty preference, and difficulty preference correlates significantly with the performance in the block-pushing puzzle and maze puzzle. But anything requiring more reaction based actions is more related to the hours played and whether they have dealt with such an obstacle before. Hypothesis: Low conscientiousness likes more high paced gameplay, high conscientiousness uses more items and careful planning The achievement striving facet negative correlation with moving floor puzzle and the positive correlation with talking to NPCs is significant. But both of these effects can also be attributed to gamer types since this personality facet also (negatively) correlates significantly with being a hardcore gamer. As we do not find any other correlations within the conscientiousness dimension it is more likely that it is attributed to the personality trait but rather the gamer type. The same goes for the item use and abilities which require 82 more careful planning, in fights the hardcore gamer personality facets of conscientiousness negatively correlate with these variables, which again points more towards an increase in use of items and abilities when the ability as a player goes up. Hypothesis: High extraversion means more energetic game-play, more exploration, more interaction with NPCs In table 23 in the NPC and conversation interaction section we can see that primarily friendliness and assertiveness facets correlates significantly with the amount of areas visited in the village. In table 25 we can see that the cheerfulness facet correlates significantly with the amount of NPCs talked to and the areas visited in the village. In both the maze and moving floor puzzle we can see that the activity level facet causes the player to make more mistakes. From this follows that certain facets of the extraversion dimension imply more energetic game-play, more exploration and more interaction with NPCs. Hypothesis: High agreeableness spends less time in village, follows instructions better, finds more items From individual correlations in table 28 we can see that the time spent correlates with the cooperation facet, the correlation is not very strong, most likely because other behaviour will influence the time spent in the village. The bottle stats correlates with trust, this might be because the participants with higher trust scores trusted the witch more easily. The correlations are weak regarding the agreeableness facets, the preparation is correlated much more strongly with the hardcore gamer type metrics. As such we cannot with certainty say anything about the relation between agreeableness and the time spent, the instruction following and finding more items. Hypothesis: Lower neuroticism scores result in longer playtime and lower difficulty preference In the table 15 we can see that the immoderation facet correlates strongly with difficulty preference, a gamer with a high immoderation score will likely be someone that plays a lot of games and is more likely to prefer higher difficulty settings. In the table 36 we see that no significant neuroticism component parts were found for total time spent. Instead we found that total time spent correlates strongly with imagination and artistic interest, which both correlate strongly with the ”Play Action Adventure genre often” 83 metric and that correlates strongly with the with the total time spent. As such we conclude that the immoderation facet which is linked to the hardcore gamer type is related to the difficulty preference. 8.7.3 Game literacy and difficulty preference Hypothesis: A player that performs well will like higher difficulty levels We can see in table 17 that the difficulty preference correlates significantly with the reached difficulty level in case of the puzzles. The reason that we are unable to find the same result for fights is most likely due to our metrics which only captures the relative difficulty and not the difficulty level as we do with the puzzles. With these correlations we can safely assume that within our data the participants who like higher difficulty levels also reach a higher difficulty (i.e. perform better). 9 Conclusion For this master thesis a game was created to mimic the feel of an old classic game ”the Legend of Zelda: A link to the past”, added to it were elements that were necessary for this research, the procedural content generation related to difficulty. The story created from scratch to match the game’s length and to point the player in the right direction. Generating levels via algorithms which contain enough comparable elements while keeping the game relatively interesting. We also implemented a system for adaptable difficulty to try and find support for DDA systems in games. The main purpose of this thesis was to explore the possibility of user profiling using different kinds of metrics as possible bridges between behaviour and preference. Research question 1: Can we link performance to preference? During our exploration of the performance link to preference we found that there were no significant correlations between them as such the measurement of difficulty level reached does not have a link to its corresponding game-play element type. This means that we can rule out most performance related game metrics for our preference categorization. Research question 2: Can we link personality to preference? 84 We also tried to find a link between personality scores and preference. By correlating the FFM traits and facets with the reported preference rankings we found that one of the significant correlations was also correlated with gamer type metrics. In particular the facet Conscientiousness:Achievementstriving. We also found that the agreeableness dimensions and facets correlated strongly with different types of preference, but given the social nature of what the agreeableness dimensions tries to measure we suspect one or more latent variables which are influencing the preference. Many of the constructs in the personality test were not meant to measure behaviour in a game setting, so we now have significant correlations between preference and one or more unknown underlying motivations or behaviours. This means we cannot link personality scores to preference. Research question 3: Can we link difficulty preference and game knowledge to preference? Difficulty preference, just like the performance metrics does not correlate significantly with any of the preference. As such we will rule out difficulty preference as a link to preference. Game knowledge metrics are of themselves quite broad metrics and as such it was expected that they would measure latent variables. Combining the metrics with performance and behavioural data we found that the preference for talking to NPCs decreases as the participant has played more games. However, given that the participants amount of NPCs engaged with isn’t correlated with these metrics we suspect it to be a preference towards the actual engagement. We speculate that it is the participants that have played a lot of games that can navigate a game successfully without requiring the detailed information that the NPCs have and as such skip most of the dialog. We also found a possibly nostalgic effect of the block-pushing game element type, this element occurs frequently within the The Legend of Zelda: A link to the past. Participants that had played it before had a moderately significant correlation with the preference for block-pushing. Research question 4: Should a game generation algorithm also focus on dynamic difficulty adjustment? By comparing the distributions of the ratings of each game element we found that we cannot reject the hypothesis that the data is drawn from the same 85 distribution. Therefore we conclude that our version of adaptable difficulty was not experienced significantly different from the static linearly increasing difficulty. In the case of a game generation algorithm we suspect that there should be at least a small amount of difficulty correction based on what kind of rule is added. Even though our stance is that personalisation is key to a practical form of game mechanics generation. If our data is correct it could be that difficulty might not be that important as long as it is playable and winnable and that the expected difficulty follows at least a logical pattern (such as a linear one). Adding dynamic difficulty adjustment to game mechanics generation might make the game difficulty more unstable, it could have a worse result than adding default mechanics which reduce or manage difficulty inherently. In regards to procedural generated content a dynamic difficulty adjustment implementation should be in a game if it is appropriate for the game itself, having a bad parametrized DDA system is likely no different and possibly worse than creating static scenarios from which to randomly select. Research question 5: Can we create a game that enables us to gather data to test the possibility of these links and the dynamic difficulty adjustment? We have created a game which we have used as a data gathering platform for our research. The implementation contains many elements which are relevant for our limited scope. We have successfully used these game metric in the analysis of our user profile metrics and the user ratings regarding the game and difficulty were mostly positive. The game can also be expanded or changed for later research because of the nature of the modifications. We conclude that we have succeeded in creating such a game. Research question 6: If any links can be found is there a viable player profiling solution among them? While exploring we found that many of the personality facets have underlying motivations and variables that are not captured by the personality test alone. Among these underlying variables were the gamer type metrics that told us the common personality facets among hardcore gamers. We were not able to link personality and preference as well as hoped. In our results and analysis sections we talked about possible explanations for 86 the correlations that we found, we were not successful in finding a possible explanation for all of them, but we did succeed in finding one for most of them. The personality link that is present should be researched in terms of underlying motivations and strategies that stem from them. We were not able to find within our data that performance is linked to preference of a certain game element. We did find some correlations which pointed towards gaming conventions and the amount of time a participant already spends on games. Difficulty preference was not related to any preference within our data. In the end we have not found a viable profiling solution for all of the game’s elements, either due to missing the right metrics or not having the right tools to measure the metrics. Problem statement: Can we categorize game-play preference with user profiling? Given that our data has found some very strong correlations between our chosen metrics and the preference, even though they likely point to latent variables we can see that these latent variables at least exist. Our guess is that they point to gaming conventions (game-play culture) which the player is familiar with combined with motivations for certain decisions or actions. This is based on the assumption that anything unfamiliar could be harder to understand and subsequently appreciate, additionally that the personality scores did seem to correlate mostly with the behavioural metrics which points to underlying constructs which were partially measured by the personality test. Our conclusion is that we cannot categorize game-play preference with our chosen user profiling metrics, but that it is likely that metrics exist that could lead to successful user profiling regarding preference. 10 Game Developer Insights From our list of findings there are a few that can be useful to the design process of a game developer. The following pieces of advice can be gathered from our data: • When creating a dynamic difficulty adjustment system the following should be taken into account: 87 – If performance measures are unclear or when too many variables cannot be properly measured then it is likely that the DDA will perform sub-par to designed and tested scenarios. – Players that play longer are also more likely to be hardcore gamers, which in turn will increase their difficulty preference. – Using different types of tools available and at the right moment is also a good indicator of intelligence and adaptability of the player, which in turn increases their difficulty preference. – Those that display neurotic behaviour are more likely to have a lower difficulty preference. – Those that are familiar with the conventions of your game are more likely to perform better. This could be indicated by if a player skips the tutorial sections of your game. • For when designing the environment, the players that get further into a game and that eventually get bored by the type of content will either require a change in game-play or a decrease in optional content as the game progresses. • Regarding NPCs and conversations. The players that skip conversations will expect that all the information to complete the game is available to them even when not listening to or reading what the NPCs have to say. This is something to keep in mind when the mandatory action is to perform instructions based on what is said in conversations. • Those that have more imagination are more interested in exploration, as such if your game speaks to the imagination it is a good idea to implement some form of exploration. 11 Proposed Future Work The game was designed to be used in later research as a platform for data gathering or implementation of other algorithms that require game elements that are more diverse than for example Infinite Mario. The implementation still need some work before it is completely usable as a general purpose platform like Infinite Mario. • The game engine is written in C++ which allows communications with many machine learning libraries, an API should be made available to the Lua script with which the content of the game is written. 88 • Data gathering should be automated, this would likely also be a modification to the game engine to allow the engine to contact a server through the Lua script. • Alternatively the C++ source code might be able to be hosted online which would make the game more accessible to participants. We have found many faults with the current research’ design, the scope was too large, there were too many variables to keep track of. The gathering of participants was slow, the data gathering method slowed that down even more and the project did not take advantage of the current trends. If this research would be continued then the game would have to be simplified as well as give the player more choice in game-play, the more often chosen or longest played type of game could then be considered more preferred. The research could also go more towards game generation, and provide a way for the player to interact with the generation process, the generation process would have to have the option to implement certain conventions or elements, this would limit the scope to game-play and exclude most of the added things such as NPCs and story based puzzles or preparation. The preference could then be traced back to the type of elements that have been selected or interacted with the most. This would make it more appropriate for researching game-generation aspects as well. Any future research should also consider other trait measurement tools as opposed to FFM. Brainhex might be a good starting point from which to further work out a way of categorizing game-play preference. A few possible improvements with the use of AI algorithms would be: • Implementing a more advanced form of enemy AI by using dynamic scripting [24] or best-response learning [2] to improve the dynamic difficulty adjustment. • Implementing a better parametrized generation algorithm for level generation that could make more organic structures within the levels, most likely work out the more detailed version of the already implemented version that is described in [9]. • A more detailed version of the dynamic difficulty adjustment could be implemented for the puzzles which would make use of unsupervised learning based on the game input of the player and more detailed behavioural information. 89 • Some form of game mechanic generation could be implemented which could for example change the available items or the main weapon of the player. 12 Acknowledgement Appreciation and acknowledgement goes out to S.C.J Bakkes for guiding this master thesis in the right direction and staying on as guidance even when finding work at another university. 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In Computational Intelligence and Games (CIG), 2011 IEEE Conference on, pages 197–202. IEEE, 2011. [29] Veronica Lorena Zammitto. Gamers’ personality and their gaming preferences. PhD thesis, Communication, Art & Technology: School of Interactive Arts and Technology, 2010. 92 Appendix A Demographic questionnaire Question What is your name or handle? Please fill in your age. What is your gender (biological sex)? How many hours a week do you play video games? What type of of system do play video games on? Answers or answer type Text Number Male/Female/Other 0-4 / 4-10 / 10-20 / 20+ Desktop Computer / Laptop, Console, Handheld console, Phone, Tablet, Other[Text] 5-level Likert scale I have played many different genres of video games. I play video games of the genre Action Adventure very often. What kind of difficulty setting are you drawn to? Have you played ”The Legend of Zelda: A link to the Past” before? 5-level Likert scale Very easy / Easy / Normal / Hard / Very Hard / Impossible No / Yes Table 38: This table contains the questions and possible answers posed in the demographic questionnaire. 93 Appendix B Personality test The following instruction was given at the beginning of the personality questionnaire: How Accurately Can You Describe Yourself? Describe yourself as you generally are now, not as you wish to be in the future. Describe yourself as you honestly see yourself, in relation to other people you know of the same sex as you are, and roughly your same age. So that you can describe yourself in an honest manner, your responses will be kept in absolute confidence. Indicate for each statement whether it is 1. Very Inaccurate, 2. Moderately Inaccurate, 3. Neither Accurate Nor Inaccurate, 4. Moderately Accurate, or 5. Very Accurate as a description of you. Estimated time required to fill in this questionnaire is 20 to 40 minutes. All the questions used in the personality questionnaire can be found at http://ipip.ori.org/30FacetNEO-PI-RItems.htm. The questionnaire was constructed by interleaving all questions such that no question is adjacent to a question of its own category. 94 Appendix C C.1 Game metrics Village game metrics Name name timeStamp npcsTalkedTo optionsTaken totalOptions percOptionsTaken percNpcsTalkedTo cureBrewer cureWitch apples rupees foundBottle filledBottle visitedBushArea visitedWoodsExit visitedPlaza visitedBrewerArea timeSpentVillage villageFromSave Village game metrics Type Description string character name datetime date and time of game start integer number of NPCs talked to integer number of conversation options explored integer total number of conversation options available fraction percentage of conversation options explored fraction percentage of NPCs talked to boolean got the brewer’s cure boolean got the witch’s cure integer amount of apples gathered before leaving the village integer amount of rupees gathered before leaving the village boolean found the hidden bottle in the bushes boolean filled the hidden bottle with the witch’s red potion boolean visited the area around the bushes boolean visited the northeast area behind the buildings boolean visited the plaza with the old lady and the apple merchant boolean visited the area around the brewer decimal amount of seconds spent in the village boolean player had saved in the village and continued later Table 39: This table contains the full list of logged game metrics within the village. 95 C.2 Fights game metrics Fight game metrics: initial inventory, enemies and room layout data Name Type Description name string character name mapID string ID of the current level egg integer amount of manillosaur enemies spawned snapDragon integer amount of snapdragon enemies spawned hardhat integer amount of hardhat enemies spawned knight integer amount of knight enemies spawned boss integer has boss been spawned startLife integer amount of life the player had at the start of the fight hasBow boolean does the player have a bow hasMirror boolean does the player have the magic mirror hasFairyBottle boolean does the player have a bottle filled with a fairy hasGlove boolean does the player have the power gloves that enables white rock lifting hasGlove2 boolean does the player have the upgraded power gloves that enables black rock lifting hasBomb boolean does the player have the bomb bag pitfalls integer the length where pitfalls / water meets walkable ground spikes integer the length where spike floor meets walkable ground inside boolean is the current map inside the caves surface integer amount of 8×8 pixel squares of walkable space available Table 40: This table contains the full list of logged game metrics of the fights. 96 Name finished swordHits bombUsage bowUsage mirrorUsage applesUsage explodeHits thrownHits fightTime dirChange lifeLost clangs uselessKeys moving standing percStanding avgAggro killEgg killSnapDragon killHardhat killKnight Fight game metrics: end of fight data Type Description boolean finished off all remaining enemies without leaving the area integer times the enemies were hit with the sword integer times the bomb bag was used in the fight integer times the bow was used in the fight integer times the magic mirror was used in the fight integer times an apple was used in the fight integer times the enemies were hit by a bomb explosion integer times the enemies were hit by a trown bush or rock decimal seconds spent fighting integer times the player has changed the direction of the character integer life the player lost during the fight integer times the sword of a knight was hit during the fight integer input keys that have been pressed that do nothing decimal seconds spent moving during the fight decimal seconds spent standing still during the fight fraction percentage of time standing still vs. moving around decimal average enemies chasing the player over time integer manillosaurs killed integer snapdragons killed integer hardhats killed integer knights killed Table 41: This table contains the full list of logged game metrics of the fights. 97 Name free freezed grabbing hurt stairs loading spin swing tap carry lift treasure useItem falling backOnFeet Fight game metrics: hero states recorded Type Description integer character returned to idle state integer character’s control has been frozen integer character is grabbing the environment integer character went into the hurt animation integer character went into the stairs animation integer character is loading a sword spin attack integer character is performing a sword spin attack integer character swings his sword integer character taps the environment with his sword while loading a sword spin integer character is carrying an object above his head integer character lifts an object above his head integer character opens a treasure chest integer character uses an item from his inventory integer character is falling in a pit or body of water integer character is placed back on a walkable surface after falling Table 42: This table contains the full list of logged game metrics of the fights. 98 C.3 Puzzle game metrics Name name mapID puzzleType difficulty timeSpent retries gotHurt falls deaths quit completed averageVFMtime Individual puzzle game metrics Type Description string character name string ID of the current level string type of puzzle (maze / moving-floor / sokoban) integer difficulty rating (1-5) decimal seconds spent on the puzzle integer times the sokoban puzzle was restarted integer times the player got hurt during maze or moving-floor puzzle integer times the player fell in a pit during the maze puzzle integer times the player died during the puzzle boolean player has pressed the optional quit button in a sokoban puzzle that becomes available after 135 seconds boolean puzzle is completed by reaching the farthest side decimal average seconds a player took before moving his first block after restarting the sokoban puzzle Table 43: This table contains the full list of logged game metrics of individual puzzles. 99 Puzzles per segment game metrics Name Type Description name string character name mapID string ID of the current level totalTime decimal time spent puzzling sokobanTotalTime decimal time spent on sokoban puzzles sokobanRetries integer times the player restarted a sokoban puzzle sokobanQuits integer times the player quit a sokoban puzzle sokobanPuzzles integer sokoban puzzles encountered sokobanVFM decimal average of averages of the the seconds a player took before moving his first block after restarting the sokoban puzzle movingFloorTotalTime decimal time spent on moving-floor puzzles movingFloorGotHurt integer times player got hurt during moving-floor puzzles movingFloorDeaths integer times player died during movingfloor puzzles movingFloorPuzzles integer moving-floor puzzles encountered mazeTotalTime decimal total time spent on maze puzzles mazeGotHurt integer times player got hurt during maze puzzles mazeFalls integer times player fell into a pit during maze puzzles mazeDeaths integer times player died during a maze puzzle mazePuzzles integer maze puzzles encountered Table 44: This table contains the full list of logged game metrics of puzzles per level segment. 100 C.4 Exploration game metrics Exploration game metrics: initial settings, rewards and rooms Name Type Description name string character name mapID string ID of the current level staticDifficulty boolean static difficulty enabled branchLength integer length of the optional path branches fights integer number of fight-type rooms puzzles integer number of puzzle-type rooms outside boolean is outside or forest themed missionType string tutorial / normal / boss type missions which determines layout fightsPuzzlesRatio fraction the ratio of fights to puzzles totalRooms integer total amount of rooms in the level roomsVisited integer amount of rooms entered uniqueRoomsVisited integer amount of unique rooms entered percUniqueRoomsVisited fraction percentage of rooms visited at least once rewardsAvailable integer optional treasure available rewardsRetrieved integer optional treasure retrieved heartAvailable boolean one optional treasure contains heart container heartRetrieved boolean heart container retrieved percRewardsRetrieved fraction percentage of rewards retrieved fightsEncountered integer fights encountered by the player fightsFinished integer amount of fights completely cleared of enemies by the player puzzlesEncountered integer puzzles encountered by the player puzzlesFinished integer puzzles finished by the player typeEncounterRatio fraction encounter ratio of fights vs. puzzles Table 45: This table contains the full list of logged room related game metrics of the exploration for a single level. 101 Exploration game metrics: time Name Type Description timeSpent decimal time spent in the level timeSpentOptional decimal time spent in the optional areas timeSpentMain decimal time spent in the main route areas timeSpentPuzzling decimal time spent on puzzles timeSpentFighting decimal time spent fighting timeSpentOther decimal remaining time spent elsewhere fightsPuzzleTimeRatio fraction time ratio of fights vs. puzzles percTimeSpentOptional fraction percentage of time spent in optional areas percTimeSpentMain fraction percentage of time spent in the main route areas Table 46: This table contains the full list of logged time related game metrics of the exploration. C.5 In-game questionnaire Name exploration puzzles puzzlePreference fights overallExperience Level segment questionnaire Type Description likertscale The player agrees that he liked the (1-5) amount of exploration available likertscale The player agrees that he liked the (1-5) challenge that the puzzles brought string Puzzle the player preferred: maze, moving-floor or block-pushing (sokoban) likertscale The player agrees that he liked the (1-5) challenge that the fights brought likertscale whether the player agrees that he (1-5) liked the overall feel and theme Table 47: This table contains the logged game metrics of the in-game questionnaire about perceived challenge and the enjoyment of the level segments in between shops. 102 Appendix D Post-Game questionnaire Question Once again please fill in your name or handle. I never got lost during the game. I liked to explore during the game. I went exploring because... I stopped exploring because... I spent about this much time playing the game (estimate) I spent more time trying to explore than to find my way to the next level. I spent more time fighting than puzzling. I encountered more puzzles than fights. I tried to prepare as much as possible before heading out of the village. I talked to as many characters as possible. I thoroughly explored all the conversation options. I explored every nook and cranny of the village. I found the witch to be more trustworthy than the brewer. Answers or answer type Text 5-level Likert scale 5-level Likert scale ...of the rupees and items, ...of possible secrets, ...I want to explore, Other[Text] ...of the difficulty, ...I got bored with the game, ...I wanted to finish the game fast, ...I explored everything there was to explore, Other[Text] 10-25 min. / 26-40 min. / 41-55 min. / 56-70 min. / 70+ min. 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale Table 48: This table contains the first part of the questions and possible answers posed in the post-game questionnaire. 103 Question I found the puzzles to be too easy. I found the puzzle difficulty to be fitting for this type of game. I think that I finished the blockpushing puzzles quickly. I found myself having to reset the block-pushing puzzle a lot. I found the block-pushing puzzles to be too hard. I found myself thinking a long time before making my first move with the block-pushing puzzles. I think that I finished the movingfloor puzzles quickly. I often got my character hurt during a moving-floor puzzle. I found the moving-floor puzzles to be too hard. I think that I finished the maze puzzles quickly. I often got my character hurt during a maze puzzle. I found the maze puzzles to be too hard. Answers or answer type 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale Table 49: This table contains the second part of the questions and possible answers posed in the post-game questionnaire. 104 Question I often used my environment to deal with enemies. I often used items (bombs, bow, mirror, apples, etc.) that I had at my disposal. During a fight I would move around quite a lot. During a fight I would swing my sword as many times as possible. During a fight I would time my sword swings as best I could. I often got my character hurt during a fight. I found the fights to be too hard. I found the combat difficulty to be fitting for this type of game. I think that I finished the fights quickly. I found the boss fight to be too hard. My favorite strategy during fights regarding enemies is... I found that the game was fun to play. I found that the story presented in the game was interesting. Rank all the elements in order of that which you liked most. [Optional feedback box] Answers or answer type 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale 5-level Likert scale ...luring them close / ...rushing towards them / ...avoiding them / ...softening them up with items/rocks/bushes 5-level Likert scale 5-level Likert scale (most enjoyable)1-6(least enjoyable) ranking ofthe categories Fights, Block-pushing puzzle, Dark maze, Moving floor puzzle, Talking to characters, Walking around/exploring Text Table 50: This table contains the third part of the questions and possible answers posed in the post-game questionnaire. 105 Appendix E Website Figure 23: The entry page of the website, it displays information about the research and what a participant gets by participating in the research. 106 Figure 24: A summary of what is required for participation and information about the engine. 107 Figure 25: The instructions given to the participant to complete the experiment. 108 Figure 26: The standard control scheme and contact information. 109
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