Investigates the role of visuals in the instructional and evaluation phases of a high school biology unit on the human heart. Results indicate that the instructional strategy of implementing visualization in both the presentation and evaluation phases is a viable instructional variable. Forty-four references are listed. (Author/MER)

Argues that visual literacy should be studied through a cognitive approach, and describes principles of punctuating and structuring that can be used to develop a new standard of experimental validity. Triadic interaction theory and the role of strategies in research are discussed, as well as a new orientation to research. (BK)