The effects of anchoring in interactive multiple criteria decision making solution methods

In this paper we describe an experiment that examines the effects of the anchoring and adjustment bias in two different interactive MCDM solution methods. Anchoring is a well documented psychological bias in decision making, where the starting point of a decision process often greatly affects the final outcome. In this experiment we consider a three objective, continuous decision problem with multi-dimensional outcomes and solved using a free search interactive method and the Zionts and Wallenius method. Results suggest that subjects are anchored by the starting point in the Zionts and Wallenius method, but the effect of anchoring is not significant in the free search method. We hypothesize that the anchoring effect is significantly affected by the structure of the solution method, and offer suggestions for using and designing interactive MCDM solution methods.