A variable that may be associated with performance improvements is goal setting (within and across days). Easy-to-achieve goals will likely produce gradual trends in improvement and difficult-to-achieve goals steeper trends. The purpose of the current experiments was to study the effects of setting easy-to-achieve and difficult-to-achieve goals on the level, trend, and variability of correct, incorrect, and skip responses for math tasks when reinforcement contingencies and numbers of practices were held constant. Five undergraduate students answered math problems on flash cards in 30s timings. Single case design elements were used to evaluate the effects of different types of goals on the speed and accuracy of performance. The results revealed that goal setting primarily increased the frequency of incorrect responses and both the level and trend of skip responses. The implications of these findings and other important variables that influence the effectiveness of goal setting are discussed. In addition, the authors suggest guidelines to follow when implementing goals to improve performance.