Measurement methods for product evaluation

Abstract

Among the many tasks designers must perform, evaluation of product options based on performance criteria is fundamental. Yet I have found that the methods commonly used remain controversial and uncertain among those who apply them. In this paper, I apply mathematical measurement theory to analyze and clarify common design methods. The methods can be analyzed to determine the level of information required and the quality of the answer provided. Most simple, a method using an ordinal scale only arranges options based on a performance objective. More complex, an interval scale also indicates the difference in performance provided. To construct an interval scale, the designer must provide two ba..