A MODEL FOR REALISM OF CONFIDENCE JUDGMENTS - IMPLICATIONS FOR UNDERCONFIDENCE IN SENSORY DISCRIMINATION

In a recent issue of this journal, Bjorkman, Juslin, and Winman (1993) presented a model of the calibration of subjective confidence judgmen ts for sensory discrimination which they called ''subjective distance theory.'' They proposed that there was a robust underconfidence bias i n such judgments, that the model predicted such a bias, and that two d ifferent models were needed for the calibration of subjective confiden ce for cognitive judgments and for sensory ones. This paper addresses issues they raised. It points out that they have not presented a new m odel, but rather a portion of a more general one, the ''decision-varia ble partition model'' originally proposed in Ferrell and McGoey (1980) . This paper explores properties of the model and shows, contrary to B jorkman, Juslin, and Winman's hypotheses, that the model does not pred ict underconfidence that the ''hard-easy effect'' can, be observed wit h sensory discriminations, and that the model fits not only sensory, b ut also cognitive judgments.