Universal Principles of Design, Updated and Expanded Third Edition

005 Affordance

The physical characteristics of a thing that influence its function and use.

The form and features of a thing make it well suited for certain functions and uses and poorly suited for others. For example, wheels afford rolling, stairs afford climbing, and levers afford pulling; whereas cinder blocks negatively afford rolling, featureless walls negatively afford climbing, and buttons negatively afford pulling.1

When affordances are good, things perform well and are intuitive to use. When affordances are bad, things perform poorly and are hard to use. For example, a door with a handle affords pulling. Sometimes, doors with handles are designed to open only by pushing. The affordance of the handle conflicts with the door’s function. ...