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In an IRT>15-s schedule, either the number of points was fixed or a lesser number was awarded the later a response occu rred during the 5-s LH. As an additional means for enhancing feedback about performance, a response that exceeded the LH yielded minimal reward (vs. no reinforcer and clock reset), thus allowing differentiation between excessively long IRTs and anticipatory responses. It was expected that the "graded" scale of reward magnitude, coupled with delivery of one point for exceeding the LH, would increase precision of performance. Providing a point for overestimations did increase the percentage of IRTs falling within the LH, and graded magnitude of reward did enhance the proportion of IRTs taking place earlier within the LH. It was suggested that contingent incentive value, as incorporated in the present laboratory paradigms, effectively influenced performance and, in general, represents the nature of contingencies that prevail in the "real world."