MENTAL MODEL mental models are what people really have in their heads and what guides their use of things.
PRINCIPLES OF DESIGN• Make things visible• Provide a good conceptual model • Affordance • Mapping • Constraints • Feedback
VISIBILITY Just by looking the user should know the state of the system & possible actions The correct parts must be visible and they must convey the correct message. Visibility problems occur when clues are lacking or exist in excess Don’t violate these principles to make something “look good”!
AFFORDANCE Just by looking at the object, a user should know how to use it. Make the appropriate actions visible and make the inappropriate actions invisible.
MAPPING Controls and displays should exploit natural mapping. Natural mapping takes advantage of physical analogies and cultural standards. Physical: Steering wheel Cultural: red means stop, green means go.
CONSTRAINTS Constraints limit the ways in which something can be used. Ensure correct procedure by making it impossible to do otherwise.
FEEDBACK Feedback are clues given to the user that they have been successful Good design contains feedback
ITERATIVE DESIGN “Iterating is designing and, more speciﬁcally, understanding what one is designing through actually creating it. . . . Iterative design also means that until you have actually built what you are designing, you are not going to be able to fully understand it. --Anders Ramsay, http://www.andersramsay.com/2009/03/01/three-reasons-to-start- designing-iteratively“learning by creating” “learning by reworking”
USER CENTERED DESIGNdesign discover deﬁne http://www.vinq.com/ucd.html