The setting and maintenance of criteria representing levels of confidence.

The theory of criterion setting developed by the 1st author and T. C. Williams (see record 1984-08523-001), which postulates control of decision criteria by a long- and 2 short-term mechanisms, can provide an account of sequential dependencies. The theory is applied to the question of whether criteria are all set and maintained in the same way or whether they fall into 2 groups, controlled in accordance with different rules. Evidence from 2 experiments, with 6 18–32 yr old Ss, using an auditory detection task indicates that (1) the short-term (tracking) mechanism that responds to momentary change in the probability of the signal primarily controls the (categorical) criterion that determines the category of response (yes or no) and (2) the criteria that determine levels of confidence are maintained at constant separations from the categorical criterion. A new sequential dependency, the criterion divergence effect, is reported. It is shown that this is mediated by sequentially determined changes in sensitivity, and a model for this is derived.