§7-Cognitive aspects Flashcards
Why Cognitive Psychology for Interaction Design?
- understand the world view of the user
- to design the interface in a way which is consistent with the world view
EXAMPLES?
List five tools for understanding how humans think
- The Model Human Processor
- Core aspects of cognition
- Memory
- Gestalt psychology
- Human perception
(tool 1) three components of the model human processor
- perceptual
- cognitive
- motor
Describe the perceptual subsystem
- input: senses (visual, auditory, haptic)
- fed into visual image store, audio image store, via perceptual processor
1. information is stored in memory (sensory, working/ST, LTM)
Describe the cognitive subsystem
- output of perceptual subsystem is fed into working memory (STM)
- exchanges between LTM, STM and the cognitive processor
- output from working memory to the motor subsystem
Activities of the cognitive processor
- reasoning,
- skill acquisition
- error feedback
Describe the movement subsystem
- output from cognitive subsystem into motor processor
2. motor processor drives the movement response
Processor cycle times and consequences
- Tperceptual > Tcog, Tmot
- Tperceptual is shorter for more intense stimuli
- Tmotor ~ Tcog
- allows a system designer to predict the time it takes to complete a task
(tool 2) list four core cognitive aspects
- perception and recognition
- memory
- reading, speaking listening,
- problem solving,…, learning
what are the three types of memory, how is info transferred between them
Three types of memory
- sensory buffers
- short term memory
- long term memory
- attention moves info from sensory buffers to STM
- rehearsal moves from STM to LTM
- recall moves info from LTM to STM
Properties of sensory/perceptual memory
- buffers for stimuli, passive (only moved to STM if user pays attention)
- constantly overwritten by new information (kept for ~0.5 s before overwritten)
- either overwritten and lost or passed into a more permanent memory store
What is the role of attention
- passes information from sensory memory to STM
- defined as concentration on one out of a number of competing stimuli
Design implications arising from the properties of sensory memory
- cannot assume that if a person heard or saw a message 5 secs earlier, they will still remember it (may have been overwritten / not received attention)
- keep message displayed until not needed; or make it so that the user can apply the information immediately.
- as focus is directed towards the information, it moves to STM, where it persists for < 10 seconds
Consequences of human short term memory limitations
- rapidly accessible
- transient
- limited capacity of 7±2 chunks
- information subject to interference
- items are lost from memory if not rehearsed
Principle of chunking + examples
- STM can store 7±2 chunks, mainly regardless of how complex those chunks are
~ STM constrained by number of chunks not basic elements (e.g. digits)
Patterns can be useful as aids to memory by imposing chunks
Examples
- long list -> categories : thrashing
- divide up a phone number/registration plate
- divide up menus
Issues about storage of information
- rehearsal to move info from STM to LTM
- total time hypothesis – retention is proportional to rehearsal time
- distribution of practice effect – optimise retention by spreading learning over time (fragmented and repeated rather than massed)
- structure, meaning and familiarity makes information easier to remember (interface metaphors)