The term affordance was invented by the psychologist James J. Gibson (1904-1997):
“The affordances of the environment are what it offers the animal, what it provides or furnishes, either for good or ill” (1979, p.27).
He introduced the concept by referring to the relationship between the non-human animal (water bugs and bears) and its environment, though he and others also developed the concepts in the relationship between people and designed artefacts.
Affordances are properties of an environment that we identify readily as we consider the relationship between ourselves and the place we are in. Think of a doorway in a building. A surveyor might measure the doorway in terms of width, height and the materials of its frame. But an assessment of the affordance of the doorway depends on who the might use it.
For someone with full mobility it affords convenient passage from one space to another in the building. For someone is a wheelchair it may afford an impediment to movement, especially if there’s a step, the doorway is narrow, or the door swings towards the traveller.
“As an affordance of support for a species of animal, however, they have to be measured relative to the animal. They are unique for that animal. They are not just abstract physical properties. They have unity relative to the posture and behavior of the animal being considered. So an affordance cannot be measured as we measure in physics.” (1979, 127-128)
Properties are abstract. Qualities imply a value judgement. Affordances are situated. To describe the world in terms of affordance avoids us having to foreclose on the issue of what is the actual circumstance independent of our experience and observation.
The concept of affordance has currency in the digital domain, in particular as we think of interaction or user experience (UX) design: the affordance of a box on the screen for entering your password, the buttons on a smartphone, an emoji, or indeed a whole software package, platform or service.
Encrypted communication systems and cryptographic methods carry affordances, and are complicit in the affordances of the systems they protect, enable and exclude, depending on the user – as does a doorway for someone traversing through a building. Affordance will vary amongst users, and operators, and pertains to the elements and infrastructures of any city. See previous posts that mention affordance.
- Anon. 2021. Affordances. Interaction Design Foundation. Available online: https://www.interaction-design.org/literature/topics/affordances (accessed 16 October 2021).
- Gibson, James J. 1966. The Senses Considered as Perceptual Systems. London: Allen and Unwin
- Gibson, James J. 1979. The Ecological Approach to Visual Perception. Boston: Houghton Mifflin
- Norman, Donald A. 2002. The Design of Everyday Things. New York: Basic Books