Granularity in the design of interactive illustrations

We describe some issues in designing and building educational Java applets for an introductory computer graphics course. The design problem involves balancing educational goals of building intuition about fundamental concepts in a domain against heterogeneity both in subject material and in student backgrounds. We present our design approach for resolving these forces --- fine-grained units addressing small concepts --- and discuss its effects on other areas including hypertext structure, interface design, and software engineering.