Signifier

A signifier is any perceivable cue that tells someone what they can do, what is happening or where to go. Don Norman defines it as "some signal in the physical or social world that can be interpreted meaningfully" (jnd.org ): Signifiers, not affordances). In games, signifiers are the handholds, lights, colours, sounds and props that tell the player a ledge is climbable or a door leads on.

Norman introduced the term to separate two meanings of affordance. An affordance is what the world lets you do; a signifier is how you know. In his words: "The perceivable part of an affordance is a signifier" (jnd.org ): Signifiers, not affordances).

#Affordance and signifier in practice

Norman argued that designers had stretched "affordance" to mean any visual hint, and that what they cared about was the hint. His blunt advice: "Forget affordances: what people need, and what design must provide, are signifiers" (jnd.org ): Signifiers, not affordances).

For game teams, separating the two clarifies bug reports. If players can't find a climbable ledge, the climbing mechanic (the affordance) works. The missing part is a signifier, so the fix lies in art, light or layout rather than code.

#Kinds of signifier

Norman points out that signifiers can be deliberate or accidental, and that the person reading them often can't tell which, and doesn't need to (jnd.org ): Signifiers, not affordances).

• Deliberate signifiers are placed on purpose: a scrollbar showing "how much more of the document remains", or a flag placed to show wind direction (jnd.org ): Signifiers, not affordances). In games: a lit doorway, a painted handhold, a waypoint.
• Accidental signifiers arise on their own. Norman's example is a train platform: "People milling about the platform? The train has not arrived"; an empty platform means "oops, you missed it" (jnd.org ): Signifiers, not affordances). In games: footprints in snow, a trail of bodies, a worn path.
• Social signifiers are those "created or interpreted by people or society" (jnd.org ): Signifiers, not affordances). Norman's example is desire lines, "the trails made by people's footsteps across fields" (jnd.org ): Signifiers, not affordances). In multiplayer, other players' movement, pings and bullet holes are social signifiers.

Emilia Schatz's four kinds of game affordance (explicit, defined, cultural and inferred) are, in Norman's vocabulary, four kinds of signifier: a glowing pickup, yellow paint, a recognisable ladder, and a cue the player deduces from the game's rules (80 Level: Defining Environment Language for Video Games). See affordance for detail.

#Examples from games

#Related terms

affordance · shape language · wayfinding · landmarks · environmental storytelling · set dressing and art passes · focal point

#Further reading and watching

• Don Norman, The Design of Everyday Things — the classic book on everyday usability, first published in 1988, in which Norman brought "affordance" into design. Beginner, paid book.