- Definition: The fundamental properties of something that determine how it could be used.
- Insight: Reducing the possible applications of something can increase the clarity of its affordance; conversely increasing the features of something could make it more versatile but reduce the clarity of its affordance and make it less easy to use.
- Reference: Donald Norman: "Affordances provide strong clues to the operations of things. Plates are for pushing. Knobs are for turning. Slots are for inserting things into. Balls are for throwing or bouncing. When affordances are taken advantage of, the user knows what to do just by looking: no picture, label, or instruction needed."