Affordance – a concept originally developed by psychologist James Gibson to make an argument about perception and how humans act on something independently from the perceived physical attributes of that thing. Don Norman adopted this concept into the design world. Describes the aesthetic properties of an object that communicate what you can do with that object. Affordance is relative based on one’s ability and experience, e.g. a chair affords sitting on it by adults, but not by children. e.g. an Apple CD reader has a slot of certain width, thickness, and shape that affords our understanding of how to use it. e.g. in Word 1989, affordance is literal – that is, buttons are 3D in order to indicate which parts of the interface are clickable. The current Word interface is more subtle – buttons are no longer outlined because the program is no longer designed for first time users. It is important to make sure that manipulatable parts of one’s design come across as such to the user and that their purpose is clear.

Contributed by Kahului Foster and Waverley He