i

Affordance

STR·07 · 7 of 11

The perceivable properties of a thing should announce what can be done with it.

documented A named, findable source says this. Why: Gibson 1979 coined it, Norman 1988 imported it, Norman 1999 corrected the drift. All three are citable, which is why the drift is documentable.

The same task, built twice

Both panes below are real interfaces. They respond, they can be got wrong, and each is timed from your first move in it. The times are not a study — two panes, one reader, no controls. They are here to make a difference you can feel into a number you can see, and nothing is recorded or sent anywhere.

Your task

Find the control that submits this application, and press it.

No signifiers—

Application · step 3 of 3

Review your answers Terms and conditions Save and come back later Reference AC-4471 Submit application Contact the team

Six pieces of text. Two are buttons, one is a link, three are labels, and nothing on screen distinguishes them until you hover — which a touch screen does not have.

Announced—

Application · step 3 of 3

Review your answers Terms and conditions

Reference AC-4471

Stuck? Contact the team

The same six. The button looks pressable, the link looks like a link, and the labels look like labels. Nothing here is decoration; every difference is doing work.

What to watch Your wrong-click count on the left. Norman's later correction is the useful one — what a designer controls is not the affordance but the signifier, the perceivable hint that the affordance is there at all.

The principle

OriginJ. J. Gibson (1979) coined it for ecological psychology — what an environment offers an animal; Norman (1988) imported it, then spent years clarifying that design means perceived affordances and later offered "signifiers" for the visible layer. The drift is part of the entry.
EvidenceThe Norman door downstairs; flat design's discoverability crisis and the partial return of borders and shadows measure the cost of hiding the announcement.
Limits & misuse"It affords clicking" applied to anything clickable makes the word mean nothing. Affordance is a relationship, not a coat of paint — and citing Gibson while meaning Norman is this stairwell's favorite pedantry, indulged exactly once, here.