What does drawing reveal about thinking?

Drawings are an integral part of the dialogue a designer conducts with him or herself during design. They are a kind of external representation, a cognitive tool developed to facilitate information processing. Drawings differ from images in that they reflect conceptualizations, not perceptions, of reality. For a particular domain, sketches use a small set of segments or elements that map the critical elements of the domain. It is proposed that the choice of and representation of elements and the order in which they are drawn reflect the way that domain is schematized and conceptualized. Support for this claim is gathered from research on sketch maps, graphs, and geometric analogy solution