Computational Sketch Analyser (CSA): Extending the Boundaries of Knowledge in CAAD

Computer Aided Design (CAD) was first developed in the 1960’s and has evolved to become an intricate part of architectural practice. However, one of the most time consuming phases of the design process and the one that makes the greatest demands on the designer, the conceptual design process, is still not fully supported by current computational tools. Goel (1995) argued that sketching, in this early phase of design, plays a critical role in the inception and future development of creative ideas. Designers at the conceptual stage, rely on sketching as a form of visual reasoning for the exploration of creative ideas. Through interaction with the sketch designers evolve the design problem space, so that it moves from an ill-defined set of constraints to the identification and resolution of creative ideas. This paper focuses on the cognitive problem-solving strategies of professional architectural designers and their use of external representations for the production of creative ideas. Using a new form of protocol analysis (Computational Sketch Analysis), the research has analysed five architects’ verbal descriptions of their cognitive reasoning strategies during conceptual designing. It compares these descriptions to a computational analysis of the architects’ sketches and sketching behaviour. The paper describes how the current research is establishing a comprehensive understanding of the mapping between conceptualisation, cognition, drawing, and complex problem solving. The paper proposes a new direction for Computer Aided Architectural Design tools (CAAD). It suggests that in order to extend the boundaries of knowledge in CAAD an understanding of the complex nature of architectural conceptual problem-solving needs to be incorporated into and supported by future conceptual design tools.