Product design is an unstructured but logical problem, for which
successive iterations of synthesis and analysis eventually produce
approximations to the desired results [Paz-Soldan 89]. Observation of
design practice has led to a growing body of research that attempts to
understand, or at least capture, what the designer does in the hopes of
aiding the higher level design processes. Recent work has revealed
some problems with the synthesis techniques adapted by designers in
the mechanical domain [Finger 89]. The problem with our progress so
far is that