A wealth of empirical evidence has now accumulated concerning animals' categorizing photographs of real-world objects. Although these complex stimuli have the advantage of fostering rapid category learning, they are difficult to manipulate experimentally and to represent in formal models of behavior. We present a solution to the representation…

Maintains that having students estimate the size and width of a class waste paper can (placed on a desk) is a simple and effective way of illustrating perceptual distortion. Tests show that people will consistently overestimate the height of the can, allowing for a useful discussion on sensory distortion. (MJP)