Preference Inconsistency in Multidisciplinary Design Decision Making

Abstract

A common implicit assumption in engineering design is that user preferences exist a priori. However, research from behavioral psychology and experimental economics suggests that individuals construct preferences on a case-by-case basis when called to make a decision rather than referring to an existing preference structure. Thus, across different contexts, preference elicitation methods used in design decision making can lead to preference inconsistencies. This paper offers a framework for understanding preference inconsistencies, giving three examples of preference inconsistencies that demonstrate the implications of unnoticed inconsistencies, and also discusses the design benefits of testing for inconsistencies. Three common engineering and marketing design methods are discussed: discrete choice analysis, modeling stated versus revealed preferences, and the Kano method. In these examples, we discuss perceived relationships between product attributes, identify market opportunities for a “green” product, and show how people find it is easier to imagine delight rather than necessity of product attributes. Understanding preference inconsistencies offers new insights into the relationship between user and product design.