In the science of design, system image is a representation of the use of an object or device that is provided by the object itself, as well as the written material that may accompany it (Norman, 2002).  It is a mental representation of a device that is formed by the user of the device.  People form system images “entirely from their observations of the product – from its appearance, how it operates, what feedback it provides” (Norman, 2004, p. 75).  In other words, designers must communicate the purpose of their product using only its system image.  As a result, a good system image is one that conveys proper usage to the user.  With respect to embodied cognitive science, the development of computers and robots that are capable of emotionally interacting with users  (Breazeal, 2002) is a sophisticated form of designing appropriate system images.  “Facial expressions and body language are part of the ‘system image’ of a robot, allowing the people with whom it interacts to have a better conceptual model of its operation” (Norman, 2004, p. 163).

References:

1. Breazeal, C. L. (2002). Designing Sociable Robots. Cambridge, Mass.: MIT Press.
2. Norman, D. A. (2004). Emotional Design: Why We Love (Or Hate) Everyday Things. New York: Basic Books.
3. Norman, D. A. (2002). The Design Of Everyday Things.  New York: Basic Books.

(Added November, 2010)