Effects of success probability and instructed adjustment criteria in a probability learning task: a within-subject replication

Abstract

A study was conducted to evaluare the interactions between instructions specifying different criteria of adjustment to a probability leaming task, and different values and distributions of the effective probability of success. A within-subject desígn was employed, in which halfthe experimental subjects were exposed to changes in instructions between scssions and to repeated changes in probability within sessions, while the other half was exposed to complementary conditicns. No effects of criterion-instructions were observed on performance in the probability leaming tasks. In contrast, probability values and distributions affected the percentage of correct responses, the percentage of choíces, and changes of choice parteros. These results are examined in terms of local effects to the exposure to different probability values and distributions.