Dimensional Commensurability and Cue Utilization in Comparative Judgment.

Abstract : Subjects compared pairs of students with respect to potential college GPA. Both students had scores on one common dimension (e.g., Englist skills) and a unique dimension (e.g., Quantitative Aptitude for Student A and Need to Achieve Success for Student B). The common dimension was weighted more heavily in the comparison than were the unique dimensions. Cautioning subjects not to overweight the common dimension did not reduce the effect. In addition, the effect was equally strong whether or not the various dimensions had equal means and standard deviations. Comparisons between two stimuli along the same dimension are easier, cognitively, than comparisons between dimensions, and this commensurability factor apparently led subjects to give more weight to the common dimension. The results are congruent with a growing body of research that documents man's difficulties in processing information. Implications for applied decision making are briefly discussed. (Author)