Throughout the history of education as a social science,empirical research has been conducted on various representation modes of knowledge and their impact on learners. Although a number of nonobjective philosophies have been put forth in education, research in knowledge representations continues to be dominated by a paradigm of knowledge transfer. This chapter uses
a three-tier toolbox metaphor for media-based instructional design. The top tier addresses learning theories,the middle tier addresses multimedia models, and the bottom tier addresses specific text, visuals, audio, and animation/video design guidelines