The class of media characteristics, which is generic to them and which may be of potentially great relevance to learning, is the way in which media select, highlight, structure, and present information, i.e., their "languages" or symbol systems. How, if at all, and why do symbol systems, in general, differentially relate to cognition and learning?…

Based on the more general principle that all thinking (including reasoning) is basically perceptual in nature, the author proposes that visual perception is not a passive recording of stimulus material but an active concern of the mind. He delineates the task of visually distinguishing changes in size, shape, and position and points out the…