EXPERIMENTAL COMPARISON OF DIFFERENT APPROACHES TO DETERMINING WEIGHTS IN ADDITIVE UTILITY MODELS.

Abstract

Several studies this past decade have examined differences between holistic and decomposed approaches to determining weights in additive utility models. Some have argued that it matters little which procedure is used, whereas others strongly favored particular methods. In this study the authors address this controversy experimentally by comparing five conceptually different approaches in terms of their weights and predictive ability. The five methods are (1) multiple linear and non-linear regression analyses of ten and fifteen holistic assessments, (2) direct decomposed tradeoffs as proposed by Keeney and Raiffa, (3) a recent eigen-vector technique of Saaty involving redundant pairwise comparisons of attributes, (4) a straight-forward allocation of hundred importance points, and (5) unit weighting (i. e. , equal weighting after standardizing the attributes. In terms of findings, the methods generally differed systematically concerning the weights given to the various attributes, as well as the variances of the resulting predictions. On average, however, the methods predicted about equally well, except for unit weighting which was clearly inferior. The findings differ in this regard from the general literature.