In computer-based medical education, there is frequently a need to present students with pictorial data representative of the natural variation associated with disease presentations as well as the progression of disease within an individual. Because of the difficulty in acquiring such data, image acquisition is often the most resource-intensive phase of multimedia courseware development. In light of the resource demands associated with image content, many courseware designers do not make opportune use of image data, but rely instead upon text descriptions to provide variation in content. The resulting lack of adequate pictorial content often lessens the overall impact of the courseware. To overcome constraints imposed by the difficulty in acquiring pictorial content of sufficient richness, a methodology of generating variation in visual teaching materials has been developed through the use of morphing. These techniques have general applicability in creating variation in pictorial teaching materials in a variety of image-intensive domains.