Instructors assess the acquisition of new skills by delivering blocks of trials containing multiple operants. Mastery is evaluated as percentage correct across all operants in the block. The purpose of the current study was to investigate this traditional mastery criterion arrangement compared to an analysis of mastery at the level of individual operants. In both conditions, mastery criterion was 100% accuracy in one session. In the Set Analysis (SA) condition, accuracy was evaluated as average correct responding across all 4 target operants, or sight words, in a set. In the Operant Analysis (OA) condition, we taught 4 sight words simultaneously, assessed accuracy per sight word, and substituted new sight words into the set each time a single sight word was mastered. Overall, all 4 participants learned textual responses to sight words quicker in the OA condition, the reliability of maintenance was similar across conditions for 2 of 4 participants, and 4 of 4 participants maintained a higher or same number of responses from the OA condition compared to the SA condition. Implications for skill acquisition are discussed.