The purpose of this study is to clarify how the people, both nonprofessionals and professionals, think or deal with forms and spaces. Visualization and manipulation of forms and spaces in mind and the act of drawing interact with each other. This paper is focused on the development of esquisse drawings and offers an analysis of protocols derived from experimental investigations in which both non-professionals and professional architects were asked to design houses on paper. Through the experimental results, it was concluded that non-professionals' cognitive structure in the design task was chiefly based on the linear and behavioral perceptions, while architecturally-educated group developed the design in pattern approaches as well.