This study explores the instructional impact of using computer multimedia to integrate metaphorical verbal information into graphical representations of biotechnology concepts. The combination of text and graphics into a single metaphor makes concepts dual-coded, and therefore more comprehensible and memorable for the student. Visual stimuli help the learner establish semantic connections between the abstract and the concrete, and it is hoped that metaphoric stimuli can facilitate analogical links between the unfamiliar and the familiar. In this study, six versions of instructional materials were developed: non-graphics without metaphors (control group), static graphics without metaphors, animated graphics without metaphors, non-graphics with metaphors, static graphics with metaphors, and animated graphics with metaphors. Participating college students (n=120) were randomly assigned into the six groups and studied the materials independently. A criterion-referenced test was used to assess students' learning performance, while the Instructional Material Motivation Survey (IMMS) was used to gather attitudinal responses. Interviews and observations yielded information about how students employed graphics and metaphors for mental elaboration. Quantitative results suggested that animated graphics plus metaphorical treatment enhanced motivation the most, although metaphorical treatment seemed to be received positively regardless of what accompanied it. Furthermore, the results of the interviews and observations shed light on, among other things, how students process and interpret graphical displays and how the pace of animated presentations influences learning. As a sample of the metaphorical technique, an appendix offers a series of sequential drawings and accompanying verbal information that depict strands of genetic materials as "screwed zippers." (Contains 36 references. (BEW)