Aiding Design Decision Making: Adapting Mathematical Paradigms to Fit Designers’ Actual Needs

When designing products, designers compare complex alternatives and select one or more for further development. The quality of these selection decisions directly impacts the quality, cost and safety of the final product. Decision theoretic approaches for making systematic comparisons might help in this process, yet designers do not tend to use them. The goals of this work are to begin understanding why, and to identify future questions that may lead to solutions. This paper summarizes the results of two studies, 1) an ethnographic study of working designers in which their actual practices and needs were observed during decision making, and 2) a laboratory study in which designers were asked to use mathematical models to compare and select design alternatives. Based on these studies, we conclude that the mathematical models, as formulated, are not well suited to designers’ needs. We propose a research agenda that may lead to new approaches combining decision theoretic and user-centered methods to create tools that the average designer will be willing to use.