Previous research supports the use of a variety of error-correction procedures to facilitate skill acquisition during discrete-trial instruction. We used an adapted alternating treatments design to compare the effects of 4 commonly used error-correction procedures on skill acquisition for 2 children with attention deficit hyperactivity disorder and 3 children with autism spectrum disorder. For all participants, multiple error-correction procedures were effective; however, 1 or 2 specific error-correction procedures led to more efficient skill acquisition for each individual. These results highlight the importance of evaluating the effectiveness and efficiency of error-correction procedures for individual learners during discrete-trial instruction. We discuss the use of discrete-trial instruction with different populations, implications for using multiple measures of procedural efficiency, and several areas for future research.