Optimal Structures for Multimedia Instruction.

This final report presents the results of a two-year study of the structure of multimedia instruction. The real-world problem that has inspired this research is how to design effective multimedia instructional materials. In designing instructional materials for such media, one should use theoretically motivated and experimentally verified principles for choosing among the many possible instructional structures and representations possible using the various media involved. This report presents research aimed at exploring some basic principles of this kind. The major findings include the following: Choice of discourse type can strongly affect comprehension; this is a new result that would not have been predicted by any current theory of instruction or comprehension; Gestural coordination between visual and verbal material can significantly help comprehension; Suitable vision icons can greatly aid comprehension, even when they are not coordinated with linguistic material; Cognitive level has a very significant and systematic effect on comprehension; Manipulation of the internal structure of discourse units has significant and systematic effects; in particular, the greater the level of structure violated, the greater seems to be its effect on comprehension. To discover this effect requires a relatively fine-grained theory of discourse structure; and Inclusion of summaries, particularly initial summaries, seems to assist comprehension.