Criterion adjustment and probability matching

Abstract

Probability matching is contraindicated by the data of individual subjects (Dusoir, 1974) and by group data (Creelman & Donaldson, 1968); in general, response frequencies are not as extreme (i.e., distant from one-half) as the corresponding stimulus frequencies. This deviation from probability matching can be accounted for by at least two versions of an error-correcting model in which the subject's decision criterion may shift only after an error, but not by a model which permits criterion shifts after correct responses. One version of the error-correcting model allows us to specify the dependence of response frequency on payoff magnitude and on signal strength. The deviation from matching is consistent also with a model that assumes that, on each trial, the criterion shifts in the direction of the sensory information, regardless of response accuracy. This model is thus applicable to situations in which trial-by-trial feedback is omitted. © 1975 Psychonomic Society, Inc.