Affordance based design: a relational theory for design

After reviewing current approaches to design theory, which are based on the transformative concept of function, we argue that this basis in function limits the scope of design problems and explanatory power of current design theories. As an alternative with greater potential for explanatory power and a framework for solving a wider array of design problems, we propose that a relational theory of design is needed. Such a relational theory should mirror those currently developed in mathematics, physics, computer science, and even philosophy. We develop a relational theory for design based on the concept of affordances from perceptual psychology. Affordances help to explain the entanglement between designers, users, and artifacts-relationships that are not currently handled by function based approaches to design. Affordance based design, as developed in this paper, does not offer a radical new approach to doing design, but rather a shift in design thinking. Our focus in this paper is therefore on the explanatory power and potential innovation fostered by this change in design thinking, as illustrated through several examples, and not on specific methods.