The purpose of this study was to determine the effects of false positive and false negative feedback upon the self-efficacy and performance of high and low self-esteem experienced weight lifters. Among a group of volunteers, 65 experienced male weight lifters were classified as either high or low self-esteem following administration of the Global Self-Worth Scale (Neemann & Harter, 1986). Each was qualified by the ability to perform a one repetition-maximum (1RM) bench press between 200 to 350 lbs., which was tested through a series of trials. Self-efficacy estimates for the 1RM bench press were obtained throughout the experiment. Trial sessions were accompanied by manipulated feedback, providing the subjects with either actual, inflated, or deflated values of weights lifted. High and low self-esteem subjects performed tasks differently with respect to the type of feedback received. During the first manipulative treatments, high self-esteem subjects lifted greater weights after receiving false positive feedback and lesser weights after receiving false negative feedback. At all times, low self esteem subjects did not perform differently after the receipt of either false positive or false negative feedback. An analysis of the self-efficacy data demonstrated that predictions for 1RM bench press performances were not influenced by levels of self-esteem. However, both high and low self-esteem subjects predicted that they would lift greater or lesser weights following the administration of, false positive or false negative feedback, respectively, and both groups of subjects predicted there would be no weight differences following administration of actual feedback. Correlation analyses, conducted to determine relationships between self-efficacy and performance, indicated that during the first day of manipulative feedback treatment there was a positive relationship between self-efficacy and subsequent performance change. Previous performance change and subsequent self-efficacy change were correlated only for high self-esteem subjects during day 2 of the treatment. A regression analysis revealed that self-efficacy change was a better predictor of subsequent performance change than previous performance change. In conclusion, false positive feedback increased self-efficacy and performance of high self-esteem subjects. False negative feedback showed no significant change for either low or high self-esteem subjects. / Graduation date: 1993