affordance

Affordance is a term used in psychology, design, and related fields to describe the actionable possibilities that an environment or object offers to an agent. The concept emphasizes the relationship between the thing and the observer, such that the affordances depend on the abilities of the actor as well as the properties of the object or setting. For example, a chair affords sitting to a person of typical height, while a door handle affords pulling or turning.

The concept was introduced by ecological psychologist James J. Gibson, who defined affordances as real, relational properties that exist in the interaction between an organism and its environment. They are not merely in the mind; rather, they are about what the environment makes possible for the observer, given their capabilities. Over time, the term has been widely adopted beyond psychology, especially in design and human–computer interaction (HCI).

In HCI, Don Norman popularized the idea of perceived affordances, stressing that good design should communicate how an object can be used. Perceived affordances are what users believe they can do with an interface, and misperceptions can lead to errors or frustration. Designers also discuss signifiers (elements that indicate where action should occur) and misaligned or hidden affordances, which can mislead users about possible actions.

Affordances can be physical, functional, or social. Examples include a chair (physical: supports weight), a button (functional: activates a function), or a calendar app (social/functional: facilitates scheduling). The concept has been applied across fields such as product design, architecture, robotics, and interactive media, while critics note that its usage has broadened and sometimes loses the precise original meaning.