CALIBRATION OF SENSORY AND COGNITIVE JUDGMENTS - A SINGLE MODEL FOR BOTH

In a recent issue of this journal, Winman and Juslin (34, 135-148, 199 3) present a model of the calibration of subjective probability judgme nts for sensory discrimination tasks. They claim that the model predic ts a pervasive underconfidence bias observed in such tasks, and presen t evidence from a training experiment that they interpret as supportin g the notion that different models are needed to describe judgment of confidence in sensory and in cognitive tasks. The model is actually pa rt of the more comprehensive decision variable partition model of subj ective probability calibration that was originally proposed in Ferrell and McGoey (Origanizational Behavior and Human Performance, 26 32-53, 1980). The characteristics of the model are described and it is demon strated that the model does not predict underconfidence, that it is fu lly compatible with the overconfidence frequently found in calibration studies with cognitive tasks, and that it well represents experimenta l results from such studies. It is concluded that only a single model is needed for both types of task.