Figure 1: AARON drawing, 1987

AARON is a program designed to investigate the cognitive principles underlying visual representation. Under continuous development for fifteen years, it is now able autonomously to make "freehand" drawings of people in garden-like settings. This has required a complex interplay between two bodies of knowledge: objectspecific knowledge of how people are constructed and how they move, together with morphological knowledge of plant growth: and procedural knowledge of representational strategy. AARON's development through the events leading up to this recently-implemented knowledgebased form is discussed as an example of an "expert's system" as opposed to an "expert system." AARON demonstrates that, given appropriate interaction between domain knowledge and knowledge of representational strategy, relatively rich representations may result from sparse information.