Under some conditions, learning is improved by using a dual mode presentation involving for example, visual diagrams and auditory, rather than written text (modality effect). Under other conditions, learning is improved by asking learners to imagine rather than study instructional material (imagination effect). Both effects have been explained…

Psychological and physiological concepts about information transmission are reviewed with a view toward uncovering principles useful to the design of audiovisual teaching materials. Audiovisual materials which transmit information via the visual or auditory channels are considered, including sound motion pictures, film strips, and audio…