Creative Segment: A descriptive theory applied to computer-aided sketching

• We proposed Creative Segment theory as a description of sketching process.
• Creative Segment includes inspiration generation, expression, and visual feedback.
• Activity sequences around Creative Segments have unique patterns.
• We developed a computer-aided sketching system based on Creative Segment theory.

Sketching is a useful design method in conceptual design, but it is a complicated process. Researchers have focused on sketching process or sketching outcomes, rather than the relation of sketching process to outcomes. How do inspirations in sketching evolve into final outcomes? Finding the relation requires a proper description of the evolving process. We thus propose Creative Segment theory. Creative Segments include inspiration generation, inspiration expression, and visual feedback. The theory describes sketching process as a Creative Segment tree with the design paths as branches. Observational experiments suggested that this theory properly described the sketching process. A user-adaptive computer-aided sketching system that constructs the Creative Segment tree was developed, and its usability was tested.