THE EFFECT OF CHANGE OF CONTEXT IN COOMBS UNFOLDING THEORY

An empirical investigation of Coombs' unfolding theory was conducted i n which basic assumptions of the theory were tested. The primary conce rn was to investigate the effects upon individuals' preference judgeme nts when the presented set of scaled stimuli was changed. Two types of judgemental tasks were used to assess these possible contextual effec ts: rank order and paired comparisons, and two different sets of scale d stimuli were presented. A reliability measure was also taken as appa rent context effects could merely be due to lack of reliability. The o btained data supported the basic assumptions of Coombs' theory, and su bjects' responses were highly reliable, thus little confounding should have occurred. The change of context effects, however, were contrary to the prediction of Coombs' theory. Strong evidence for these context effects was found for both sets of stimuli and both kinds of tasks im plemented. Implications of these findings are discussed and doubts are raised concerning the usefulness of the unfolding theory in the conte xt of attitude scaling.