The Design of Everyday Things Design Psychology (POET) Psychopathology

designing for people Create a good conceptual model - controls should look like they control something – (problem space reflected in the solution space) Make things visible – e.g. faucet that doubles as a shower control Mapping - one to one, spatial Feedback.... ATM example

Visibility User needs visual and oftentimes auditory indication that the system is behaving properly –vi takes keystrokes without any indication –turning off my iPod Natural mapping between objects allows the users to complete a task without consciously figuring out how the system works.

Mapping The relationship between two or more things –Spatial (stove top) –Cultural Ever try to control a remote-controlled car? Coming toward you?

Execution and Mental Models Providing a good conceptual model of how something works, helps the user to operate a device properly Each person may have a different mental model of how to complete some task. People who grew up on analog watches... Design has to be a common model for all.

People as Explanatory Creatures Learned Helplessness - pg self blame Taught Helplessness - self blame brought on by years of dealing with bad design

7 stages of action What we’d like form the goal Acting form the intention (action toward a goal) specify the action (without ambiguity) execute the action (no fear of failure) Feedback perceive the state of the world (feedback) interpret the state of the world (what feedback means) evaluate the outcome (degree of success)

Information is in the world - pg knowledge of and knowledge how - navigating a map, using a keyboard, opening a door, etc. Great precision is not required - pg GUIs need not detail every move nor give power over every variable (MS Word mystery colors)

The power of constraints - pg (push or turn?) The conspiracy against memory - how many passwords do you need? How many numbers are you expected to remember?

who is at fault for user error? how well did the designer constrain the user? users often blame themselves, when it is the designer’s fault design must anticipate user error an important action must be reversible How many times have you left your headlights on? Left the refrigerator door open? Programmed the microwave for 120 minutes? Recorded the wrong TV program?

it’s all in the specs immerse yourself in the problem space test during the entire dream curve with the user in mind

social pressure putting aesthetics first - designer buildings, designer anything –designers are not typical users / users are not designers creeping featurism

so how much will it cost? maintenance is usually 80% of the total cost. Saving that is free money. design and testing are often cut to reduce costs, producing the opposite effect!