This chapter represents a discussion on the interactivity of how people think and react to instructional materials in general, in the light of how this interaction may be affected by multimedia. Grounded in instructional design, where first principles take a fine grained approach to identify the learning/instructional context; this chapter provides an explanation of the differing terminology used by people when referring to multimedia instruction. A Meta-Knowledge Processing Model is proposed as a courseware designing tool. Several controversial issues that surround learning with multimedia are exposed. More work is needed to unlock the mysteries that surround multimodal instructional strategy development.