Effects of Hypothesis Generation on Hypothesis Testing in Rule-Discovery Tasks

The extent to which hypothesis generation affects hypothesis-testing performance was examined in a rule-discovery task. One hundred eight undergraduates enrolled in introductory psychology were randomly assigned to conditions in which the participants, experimenter, other participants, or no one generated hypotheses before the participants were tested on three different tasks. Hypothesis-testing performance in the experimenter-supplied condition was significantly higher than in the other conditions, suggesting that generating a list of hypotheses does not in itself improve hypothesis-testing performance. Among participants who generated hypotheses, those who generated the correct hypothesis before beginning the testing were more likely to solve the problem, suggesting that poor hypothesis-generation abilities might be a barrier to hypothesis-testing performance.