Week 4: Affordance

Affordance

Based on wikipedia, An affordance is a quality of an object, or an environment, which allows an individual to perform an action. Based on Psychologist James J. Gibson introduced in his 1977 article "The Theory of Affordances", affordances defined as all "action possibilities" latent in the environment, objectively measurable and independent of the individual's ability to recognize them, but always in relation to the actor and therefore dependent on their capabilities.

Besides,the concept was introduced to the HCI community by Donald Norman in his book The Psychology of Everyday Things from 1988. There has however been ambiguity in Norman's use of the concept, and the concept thus requires a more elaborate explanation.

According to Norman (1988) an affordance is the design aspect of an object which suggest how the object should be used; a visual clue to its function and use.

Norman writes:

"...the term affordance refers to the perceived and actual properties of the thing, primarily those fundamental properties that determine just how the thing could possibly be used. Affordances provide strong clues to the operations of things. Plates are for pushing. Knobs are for turning. Slots are for inserting things into. Balls are for throwing or bouncing. When affordances are taken advantage of, the user knows what to do just by looking: no picture, label, or instruction needed." (Norman 1988, p.9)

Norman thus defines an affordance as something of both actual and perceived properties. The affordance of a ball is both its round shape, physical material, bouncability, etc. (its actual properties) as well as the perceived suggestion as to how the ball should be used (its perceived properties). When actual and perceived properties are combined, an affordance emerges as a relationship that holds between the object and the individual that is acting on the object (Norman 1999). As Norman makes clear in an endnote in Norman (1988), this view is in conflict with Gibson's idea of an affordance.

However, the information that specifies the affordance is indeed dependant on the actor's experience and culture. In other words, the misunderstanding regarding the definition of affordances has arisen because of Norman's ambiguous use of the term and his lack in separating affordances from the perceptual information that specifies the affordances.

By WONG SOON HAN