The study aimed at studying the decrease in Choice Reaction Time as a function of three frequencies of knowledge of results (KR). Sixty male and female Ss were given 36 trials under different conditions of KR. The group getting 75 % KR was the best, second carne the 50 % group and last the 25 % group. These differences were found to be significant at 0.01 level. Sex differences were also obtained, girls being better in their initial performance, though these differences were not significant.