Style is a word that people think they understand. Most people recognize artifacts like buildings and clothes as being exemplars of particular styles, and they know words like Rococo and Art Deco as names for styles. They can recognize stylistic similarities not only in one sort of artifact but also across wide ranges of different things, such as buildings, furniture, artworks, clothes, music, and even manners. However, “style” is a slippery notion: the word has been used in a variety of senses since the ancient Greeks first thought about the differences in how people wrote or painted, and it is still used to refer to different things.

Architects use sketching and diagramming in their design process to perform functional reasoning, formal arrangements, analogy transfer, structure mapping, and knowledge acquisition. This paper describes a research framework of the author's efforts in the studies of design drawings and the building of computational sketching tools to support the early conceptual design process in architecture. The first part of the paper discusses empirical studies conducted to determine or guess a designer's thought process from sketches and thus identifies domain-specific graphical symbols. It proposes a reasoning process framework of drawing marks, acts, and reacts. The second part of the paper illustrates how design support tools could be developed based on these concepts and describes the various applications of the study, such as indexing and retrieving of design drawings or images based on the recognition of geometric shapes and the spatial relationships among them.