ICS 463, Intro to Human Computer Interaction Design: 4. Attention and Memory Dan Suthers

Attention “Taking possession of” some sensory information at the cost of others Necessary for handling “high bandwidth” input with limited “processor power” An active and selective process

Related Techniques Not too much, not too little info –too much info  too much scanning –too little  can’t remember info from other contexts Structuring information to facilitate search –Group related items –Structural alignment of uniform data –Prefix with unique identifiers

Related Techniques 2 Spatial placement reflects priority and immediacy of need Color highlights foreground info Central Peripheral: File Edit Format Tools Window Help On Demand: New Open Close Save Save As Visual and audio alerting to bring attention to periphery

Automatic and Controlled Processing Controlled Attention required Conscious control Can modify Only one controlled task at a time. Multitasking difficult but possible with external prompts Automatic Not required No control Hard to unlearn Parallel tasking possible if no interference Can lose place if interruptezd (don’t know where to resume)

Some Implications If multitasking is required, provide explicit information about state … distributed cognition perspective: external representations are part of the cognitive system Two sides of the automaticity coin: –Use uniform procedures (e.g., key chords) to leverage efficency of automaticity –Reminders, confirmations: if routine, responses may become automated, useless!

Memory Recognition versus Recall –Recognition usually much easier but requires presentation of selection set Recognition and recall depends on –familiarity –imagery –context Depth of processing affects memory –Surface form versus semantics

Memory and Icons Icons good for recognition and direct manipulation tasks Concrete to Abstract, easy to hard: –Resemblance, exemplar, symbolic, arbitrary Avoid cross modal translations (verbal  visual) Multimodal representations help (labeled icons, tool tips)

Miscellaneous on memory Knowledge in the world versus knowledge in the head –Representations as external cues –Cognitive mnemonics as internal cues Commands best retrieved in context through use, not declaratively. People must explicitly learn how to access info that is not visible. (What’s in a menu, cut buffer)  Mental model