Drawing and Cognition: Descriptive and Experimental Studies of Graphic Production ProcessesWhen we do something as apparently simple as sketching a map, constructing a working diagram, or drawing an imaginary face to amuse ourselves, we utilise a complex set of abilities: perceptual, mechanical, strategic, representational, pragmatic. Peter van Sommers sets out to distinguish and describe the various layers of organisation in the drawing performances of ordinary people adults and children. Drawings, like language, have a multi layered