Chapter 2 Cognitive Aspects
Cognition
Cognition process
Attention/intention
Perception
Memory
Mental Models
Information Processing
Why need to understand users?
- Interacting with technology is cognitive
- Need to take into account cognitive processes involved and cognitive limitations of users.
- Provides knowledge about what users can and cannot be expected to do
- Identifies and explains the nature and causes of problems users encounter
- Supply theories, modelling tools, guidance and methods that can lead to the design of better interactive products
- Attention
- Perception and recognition
- Memory
- Learning
- Reading, speaking and listening
- Problem-solving, planning, reasoning and decision-making
- Selecting things to concentrate on point in time from the mass of stimuli around us
- Allows to focus on information that is relevant to what doing
- Involves audio and visual senses
- Focussed and divided attention enables us to be selective in terms of the mass of competing stimuli but limits our ability to keep track of all events.
- Information at the interface should be structured to capture attention eg: colour, reverse video, sound and flashing lights.
Text should be legible
Icons should be easy to distinguish and read
Design Implication
Icons should enable users to readily distinguish
Bordering and spacing are effective visual ways of grouping information
Sounds should be audible and distinguishable
Speech output should enable users to distinguish between set of spoken words.
Text should be legible and distinguishable from background
Tactile feedback should allow users to recognise and distinguish different meaning
Involves first encoding and then retrieving knowledge
Involve filtering and processing what is attended to
Context is important in affecting our memory
Context
Context affects the extent to which information can be subsequently
Can be difficult for people to recall information that was encoded in different context
Attention
Make Information salient when it needs attending to
Use techniques that make things stand out like color, ordering, spacing, underling, sequencing and animation
Avoid cluttering the interface with too much information
Avoid using too much because the software allows it
Processing in memory
- Encoding is first stage of memory
- The more attention paid to something, the more it's processed in terms of thinking about it and comparing with other knowledge
- The more likely it is to be rememberd
- Users develop an understanding of a system through learning about and using it
- Knowledge is sometimes described as a mental model
- People make inferences using mental models of how to carry out tasks.
Craik described as internal constructions of some aspect of the external world enabling predictions to be made.
Involves unconscious and conscious processes (images and analogies)
Deep versus shallow models
- Encoding
- Comparison
- Response selection
- Response execution
Cognitive frameworks
Involves several processes including attention, memory, perception and learning
Internal
External
Mental models
Information processing
Gulf of execution and evaluation
Distributed cognition
External cognition
Embodied interaction
Human Information Processing
Types of processors
Perceptual
Cognitve
Motor processors
Types of Memory
- working memory
- Long-term memory