1. (n.) An affordance is an action possibility formed by the relationship between an agent and its environment (J. Gibson 1977; J. Gibson 1979). For any combination of agent or environment, any given affordance either exists or does not exist. There is no middle ground. The most inclusive definition of affordances considers only the physical possibility of an action occurring. An agent does not need to be aware of the afforded action, such as the affordance of opening a secret door. This definition is rooted in perceptual psychology and its primary source is The Ecological Approach to Visual Perception by James J. Gibson (1979).
2. (n.) An affordance may refer to a perceived affordance. Perceived affordances are a subset of affordances. A perceived affordance uses a more restrictive definition that requires an agent to be aware of the affordance, either through direct perception or experience. A perceived affordance is a possible action to an agent (Norman 1988). Unlike the traditional definition, a perceived affordance is primarily a relationship between an agent’s cognition and the environment. This definition is commonly used within the humancomputer interaction (HCI) community.
3. (n.) Affordance may refer to how appealing an action possibility is to an agent, as in “this switch has affordance.” While the other definitions are dichotomous, this definition implies a magnitude (continuum) of affordance. This usage combines the ease of perceiving and/or perceived ease of performing a possible action. Since this usage refers to one or both of these qualities, this form is unclear from a theoretical standpoint.
Date of this Version
Afforded Action, Action Possibility, Functional Affordance, Perceived Affordance, Affording
Date Posted: 03 May 2013