Interface Design Human Factors

Overview Interfaces of physical objects Human Factors User-centered Design Object Language All contribute to ID concepts

General Ideas Making things easy (safe) to use User error is impossible, or at least difficult Object language: the “messages” designed into things An important aspect is affordances

Affordances Physical design features that afford some action—pushing, pressing, hooking the hand under, etc. Also shaping things so that only fit correctly Class: examples?

Affordances/Object Language Environments: sidewalks, curbs, doorways Soap dispensers in bathrooms Door handles Buttons, knobs, sliders—appliance controls Remote controls

Psychology & Human Factors People construct models of how things work Models may not match reality Examples: Chilly room, long traffic light Good design should reduce superstition

Psychology (Mapping) Mapping: if it isn’t obvious, users construct their own Spatial (placement of controls) Temporal (response follows an action) Conceptual (the big picture)

Helping Users Know What to Do Controls for different functions look different Push/Pull doors, range controls Norman’s nuclear tapper handles Switches that do different things should tell what they do

Visibility & Feedback Make important parts & information visible Progress bar for computer operation Audio feedback—if it makes sense to user

Task Structure Organizing required decisions Think of menu systems Wide and shallow: Baskin-Robbins Narrow(er) and deep(er): Subway Ideal: limit number of choices at each stage unfortunately, this doesn’t fit most tasks

General Conclusions Acknowledge user’s view of the world and the task at hand Make controls look like they do what they do Group related functions Make separate controls distinct

General Concusions Give visual cues about how things work Give visual feedback that they are working Use mappings from the user’s world Avoid relying on written directions when possible

Caveat Some tasks don’t have natural mappings They have cultural conventions (such as traffic signals) Don’t violate these!