Today’s lecture covered the theory of Affordances. This theory originates from the field of Ecological Psychology and the work of J.J. Gibson. It is best known in HCI circles through Norman’s book ‘The Design of Everyday Things.’ According to Gibson, affordances are:
“The affordances of the environment are what it offers the animal, what it provides or furnishes, either for good or ill” (Gibson, p.127)
An important aspect of the idea is that an affordance describes a potential for action in the environment in relation to a person or animal. This has proven to be a very popular concept in design, perhaps because it deals with everyday aspects of perception and interaction and relates the usability of products to their physical form (in relation to a user) in a fairly straight-forward way.
Critical Questions
- The notion of affordances has been used in subtly different ways by different authors.
- Confusion betwen ‘Affordance’, ‘Convention’, and ‘Constraint’.
- Can we really talk about screen-based buttons affording clicking?
Practical Task
Your task for this week is to collect examples of affordances. In groups, see if you can find and shoot pictures and video of products that suggest the right (or wrong) actions in comparison to what they actually afford you. You should take a picture of the product by itself, and then a video of the product and action. Each group should find three examples.
Send me your examples by Friday and I will prepare a combined presentation, which we will use for a discussion in class.
For the discussion next week, discuss within your group why some things work and others are misleading.
Slides
Lecture slides are available
Readings
There are three readings for the topic of affordances. Copies were handed out in class.
- Norman, D.A., 1990. Chapter 4 “The design of everyday things” 1st ed., New York: Doubleday.
- Gibson, J.J., 1986. Chapter 4 “The Ecological Approach To Visual Perception” 1st ed., Lawrence Erlbaum.
- Gaver, W.W., 1991. Technology Affordances. In Conference on human factors in computing systems: Reaching through technology. New Orleans, Louisiana, United States: ACM Press, p. 79-84.
Web Resources
- A well written page that focuses on the differences between Norman’s use of ‘affordances’ and the original Gibsonian formulation.
- A page from Norman that clarifies his position on affordances as focussing on ‘perceived affordances’.