G063 - HCI Design
Perception, Attention, Memory & Learning
(PALM)
(Yes ….. more Psychology!)
Learning Objectives:
At the end of this topic you should be able to:
• indicate how perception, attention, memory, and
learning affect HCI design choices
HCI Design Factors
In trying to design an HCI which:
• is easy to learn
• is easy to remember
• reduces user error
“The system designer should try to match the HCI to the
user’s mental model”
Factors to be considered will be:
• Perception
• Attention
• Memory
• Learning
Perception
• is the input from sight and sound (& touch?)
• a user will have preconceived ideas of how a
system should look and sound
•  HCI should match user’s preconceived ideas:
– colours: green for OK, red for errors
– sound: certain sounds are perceived as happy or sad
– touch: key ‘click’ when pressed  haptic feedback
Attention
• a new user may have a limited attention span
So, in order to maintain attention consider:
• Layout
– keep consistent & logical
• Quantity of information
– uncluttered screen = concise & not excessive
– too much information  disinterested user (short attention span)
• Complexity of language
– error messages should be clear and useful
– on-screen prompts use familiar terms
Memory
• an interface may be used infrequently
• can’t rely on user remembering how to use system
•  need to use links to pre-existing knowledge
– ‘keep it simple and recognisable’
– i.e. use user’s mental model
To aid memory:
• screen layouts should be consistent & uncluttered
• design should link to pre-existing knowledge
• use of colour should be consistent and sensible
Learning
• user may not use the system often
• user may not have received training
•  user has not ‘learned’ the system yet
•  system must be intuitive
Try to use:
• user’s previous experience
– standard icons that are already known
• consistent layout for different screens
– buttons always in same position = same, easy to learn physical response
• on-screen help
– helpful, simplistic language = faster to understand & correct errors