Meanings given to the term "perception" are discussed in this paper and two categories of perception theories having implications for instructional media research are identified. One category is described as extroverted because it includes theories primarily concerned with characteristics of external stimuli and the influence that the…

While researchers have made progress in understanding metaphor comprehension, less is known about the production of metaphoric language. College students (N=129) were asked to use metaphoric comparisons to describe 16 topics. They were told to imagine themselves on a trip, writing home to someone they knew well, either a peer or a child (students…

Explains the hierarchic structure of the mammalian visual system. Proposes a model in which feedback pathways serve to modify sensory stimuli in ways that enhance and complete sensory input patterns. Investigates the functioning of the system through computer simulations. (ML)

Discusses the size-weight illusion that occurs when a person lifts two equal-weight objects differing in size and perceives the larger object as lighter than the small object. Describes several inexpensive techniques for demonstrating the size-weight illusion and reviews some relevant issues concerning this phenomena. (MJP)