Signifier

A perceptible cue — visual, auditory, or tactile — that indicates how an element can or should be used, making an underlying affordance discoverable. In Don Norman’s refinement of affordance theory, the affordance is the action possibility, and the signifier is the signal that communicates it: a button’s raised edge, an underlined link, or an arrow-shaped cursor. Accessibility problems frequently arise when flat visual design strips away signifiers, leaving affordances present but invisible — especially harmful for older adults, users with low digital literacy, and users with cognitive disabilities.