Interacting with IT Systems
Fundamentals of Information Technology
Session 5
Interaction
• Interaction is process of communication that involves
two or more participants
dialogue
multilogue
Interaction
•
Interaction can be understood as a form of
request/response communication
What time
is it?
12.30pm
A
B
1. A sends a request to B
2. B sends a response to A
Interaction
• Successful interaction requires a shared language of
communication
What time
is it?
晋语
A
B
• Successful interaction requires a shared set of rules
Give me
the time
now!
What a rude
person!
A
B
Interaction
• In an interactive exchange, participants have a
measurable effect upon one another so that in the
process of the interaction the status of both is changed.
I’m late for
the dentist!
What time
is it?
A
12.30pm
B
• Both A and B now know the time
• A knows B is a reliable source of time information
• B knows A does not have a watch
Interactivity
• Interaction also occurs between human beings and
computer programs.
• The extent to which a computer program allows
interaction is known as its interactivity
• Some computer programs have high levels of
interactivity (e.g. games); others have little or no
interactivity (e.g. embedded systems)
High
Low
How interactive
is the Web ?
Embedded
systems
games
Virtual
reality
Interactive and non-interactive
elements of interfaces
What are the interactive and non-interactive elements on the Guardian homepage?
Interactivity
• Interactivity is facilitated through a combination of
hardware and software elements of an IT System
Hardware
Mouse (input)
Keyboard (input)
Speakers (output)
Monitor (output)
?
Software
Graphical user interface
Graphical User Interface
• Originally, interaction with computers was achieved
through a text-based command line interface (e.g.
DOS or Telnet)
• Now, apart from specialist or embedded systems,
human-computer interaction (HCI) is facilitated
through the use of graphical user interfaces (GUI)
Graphical User Interface
• Standard graphical
user interfaces are
constructed from
combinations of
several classes of
component
– Menus
– Controls (buttons,
combo boxes, etc)
– Display
– Status information
Graphical User Interface
• Common GUI controls
Black
United Kingdom
•What is each
one called?
White
Submit
Mr.
Mrs.
Miss.
Dr.
•What is each
one used for?
Blue
Red
Green
Enter Text
Enter More Text
sales
orders
enquiries
Designing a GUI for a Home Control
System
• Identify each element (module) of the system
Control Panel
Living Room
Heating
Lights
Kitchen
Bedroom 1
Appliances
• Identify the user requirements for the (module) interface
–
–
–
–
–
–
Switch on all lights
Switch off all lights
Switch on light groups
Switch off light groups
Control brightness of all lights
....
Designing a GUI for a Home Control
System
• Storyboard the interface
Lights
Heating
Appliances
All lights
On/off
Brightness
Light Group
On/off
Fireside Spots
• Consider
alternatives
Brightness
Maintenance
Fireside Spot 2
• Use Visio or a
similar drawing
tool to create a
storyboard or
mock-up of the
interface
Change bulb
• Make
adjustments as
necessary
Designing a GUI for a Home
Control System
• Design the Menus
– Consideration must be given to
• Conformance to standards
– Windows standards for PC applications
– Web standards for web applications
• Grouping (associating common elements)
• Weighting (giving precedence to more commonly used elements)
File
Edit
Insert
New
Open
Close
Save
Save As
Print
Undo
Copy
Cut
Paste
Clear
Select all
New Lighting
Template
User-centred Design
• Many GUIs are too complex or inappropriate for their intended
target audience and fail as a result
• This is often because end-users of IT systems are not consulted in
the design process
• User-centred design puts the user at the centre of the design
process
• By involving end-users of a system on a regular basis designers can
properly understand the needs that the system is meant to satisfy
• User-centred design helps designers to properly tailor and maximize
usability
• User centred-design methodologies include, observations,
prototyping, user-testing, heuristic evaluation
(e.g. http://www.useit.com/papers/heuristic/heuristic_list.html )
Usability
• Usability is a quality attribute that assesses how easy
user interfaces are to use.
• Usability can be defined by five quality components:
– Learnability: How easy is it for users to accomplish basic tasks
the first time they encounter the design?
– Efficiency: Once users have learned the design, how quickly
can they complete the tasks they need to do?
– Memorability: When users return to the design after a period
of not using it, how easily can they re-establish proficiency?
– Errors: How many errors do users make, how severe are these
errors, and how easily can they recover from the errors?
– Satisfaction: How pleasant is it to use the design?
Usability
• Usability considerations should inform all stages of
software development
• Development
– Focus groups
– Paper prototyping
• Testing
– Performance testing (quantifiable metrics)
•
•
•
•
Number of clicks required to perform a task
Time taken to perform a task
Number of errors made by users
Frequency of failure to complete a task
– Think aloud protocol
– Cognitive walkthrough
Accessibility
• Accessibility is closely related to usability
– Determines how easy it is for people with disabilities (e.g.
blindness, dyslexia, colour blindness) to successfully make use of
a piece of software
– Accessibility is a particular issue on the Web as a result of the
demands of the Equality Act 2010 (Replacing the Disability
Discrimination Act (DDA) 1998)
– Web content accessibility is measured against the Web Content
Accessibility Guidelines (WCAG)
– The guidelines deal with issues such as
•
•
•
•
Navigation
Readability
Page layout
Use of colour
User Manuals
• User manuals are essential elements for first time users
and for advanced users doing more advanced tasks
• Quality documentation reduces user errors and cuts out
the need for after sales support
• A user manual should comprise:
– An overview of system elements
– Task instructions: a detailed, step-by-step breakdown of how to
complete individual tasks
– A list of typical errors and how to recover from those errors
– A glossary of terms
User Manuals
• An extract from a typical user manual
FIT Session 5 – Activities
• Now do
– Activity 5 – Interacting with IT systems