Affordance
Definition
An affordance is an action possibility offered by an environment or object to an organism — what a thing lets you do.
Origin
The term was coined by the perceptual psychologist James J. Gibson, first in the 1960s and fully developed in The Ecological Approach to Visual Perception (1979). Gibson's claim is radical and frequently softened in retelling: affordances are properties of the animal–environment system, not of the object alone and not of the perceiver's mind. A surface affords support for a creature of a given weight and leg length; the same surface affords nothing of the kind to a different creature. And affordances, for Gibson, are perceived directly — we see what a thing is for, without an intervening step of inference or memory.
Norman's Version
Don Norman imported the term into design in The Psychology of Everyday Things (1988), and in doing so changed it. In Norman's usage an affordance became, in practice, a perceptible suggestion about how a thing should be used: a flat plate on a door affords pushing, a vertical bar affords pulling, a slot affords inserting.
Norman later objected to what the field had done with this, and in 1999 introduced perceived affordance and then, more decisively, borrowed the term signifier to name what designers had actually been talking about all along.[1] The distinction he settled on is worth keeping:
- An affordance is a relation that exists whether or not anyone notices it. A screen affords tapping anywhere on its surface.
- A signifier is a perceptible indication of where the useful affordance actually is. The button drawn on the screen.
Most complaints about "poor affordances" in interfaces are complaints about missing signifiers. The affordance was there; nothing indicated it.
Kinds
- False affordance. Something appears to permit an action it does not — a fake button, a decorative handle on a sliding door.
- Hidden affordance. A real possibility with no signifier — a swipe gesture nobody discovers.
- Perceptible affordance. Possibility and signifier aligned. The case designers are aiming for.
Why It Matters Beyond Design
The concept has been taken up widely in sociology and media studies to describe what platforms make easy, hard, or impossible without determining outcomes: a system that affords instant global rebroadcast of a stranger's message and affords no equivalent effort for retraction has a politics, without anyone having decided one. Used this way, affordance is a middle path between technological determinism (the technology decides) and pure social constructivism (only use decides).
The risk, noted by critics including Ian Hutchby, is that the word becomes a way of asserting causation without demonstrating it. An affordance is a possibility, not a prediction; what people actually do with it is an empirical question.
Relevance to Cyborg Anthropology
Affordance is the concept that connects an object's material form to the behaviour that grows up around it — the hinge between design decisions and culture. See frictional interfaces for what happens when the affordances a system offers do not match the goals people bring to it.
Related Reading
References
- ↑ Norman, Donald A. "Affordance, Conventions, and Design." Interactions 6, no. 3 (1999): 38–43; and The Design of Everyday Things: Revised and Expanded Edition (2013).
