Synchronous Support and Emergence in Collaborative CAAD Mary Lou Maher John S Gero Milad Saad Design Computing Unit Department of Architectural and Design Science University of Sydney NSW 2006 Australia Design is rarely an activity that is commenced and completed by an individual. The more common design environment is one in which teams of designers work together towards a final solution. In this paper we consider issues involved in the development of computer-based design environments in which teams of design professionals can collaborate, focussing on the need for visual and underlying representations which can support multiple interpretations. We consider the environment as providing a shared workspace which facilitates both communication and progression of design ideas, concepts, and drawings. In the environment presented here, the shared workspace has two focuses: the workspace that designers see and interact with, and the workspace that provides an underlying computer-based representation for persistent memory. The emphasis is on providing representations that support emergence that occurs during collaboration. Keywords: collaborative design, team design, multi-user synchronous CAAD, shared representation, shared workspace, emergence. 1 Introduction Computer-aided design (CAD) is established in the design professions as a tool for visualising and documenting a design solution. The users of CAD vary from computer operators, whose job it is to document a design for a designer, to designers themselves who wish to visualise a design while making changes and eventually final decisions regarding form. Regardless of who the user of a CAD program is, the mode of