Two studies were conducted to identify mechanisms responsible for observed "self-reinforcement" effects. In Experiment 1, using a studying task, self-reinforcement procedures did not work when they were private (i.e., when others are not aware of the goals or contingencies), but did work when they were public. Self-delivery of consequences added nothing to the effectiveness of the procedure. The data suggested that public goal setting was the critical element in the procedure's effectiveness. In Experiment 2, an applied extension, goal setting alone was effective in modifying over a long time period studying behaviors of people with significant studying difficulties, but only when the goals were known to others. Overall, the two experiments make more plausible the view that self-reinforcement procedures work by setting a socially available standard against which performance can be evaluated. The procedure itself functions as a discriminative stimulus for stringent or lenient social contingencies. The application of this mechanism to other problems of applied significance is briefly discussed.