ABSTRACT
Dynamic interactivity afforded by diagrams is beneficial because it often enables dynamic construction of new thoughts on the fly in a situated manner. A typical situation is design. Designers draw freehand sketches, often vague and ambiguous ones, and thereby see new features and relations among elements that they have drawn, ones not intended in the original sketch. The chapter explores ways that designers use sketches to dynamically construct design thoughts. Using the technique of protocol analysis, it examines the cognitive processes of experienced designers as they design through sketching. Dynamic interactivity, however, is by no means automatic when a diagram is available. During a conceptual design process, an experienced architect was likely to make unintended discoveries when he reorganized perception using this skill voluntarily. The other is in the task of multiple interpretations of ambiguous drawings.
