Focusing on the psychological processing of audiovisual materials by learners, this chapter presents and analyzes recent research on human perception, its relation to memory, and how perception is best represented in an information processing model. Topics discussed include pictorial and verbal memory, information system capacity, filtering and pigeonholing, information reduction, system overload, organizational schemata, and multimodal perception. Also considered are simultaneous and sequential information processing, transfer of information across perceptual systems, and the emerging view of the human as an information processing system. Reasons for the study of perception by instructional developers are suggested, and an argument is made for the expansion of the scientific basis of educational technology through perception research. (15 references) (Author/EW)