Previous studies on skill acquisition have taught targets in stimulus sets composed of different numbers of stimuli. Although the rationale for selection of a stimulus set size is not clear, the number of target stimuli trained within a set is a treatment decision for which there is limited empirical support. The current investigation compared the efficiency of tact training in 4 stimulus set sizes, each of which included 12 stimuli grouped into (a) 4 sets of 3 stimuli, (b) 3 sets of 4 stimuli, (c) 2 sets of 6 stimuli, and (d) 1 set of 12 stimuli. Results of all 4 participants with autism spectrum disorder show tact training with larger (i.e., 6 and 12) stimulus set sizes was more efficient than training with smaller (i.e., 3 and 4) stimulus set sizes.

Prior research has examined interventions to prevent prompt dependence from occurring during the training of novel skills. Nevertheless, the relative efficacy and efficiency of different intervention procedures may be idiosyncratic across learners, suggesting the potential benefit of an individualized assessment. The purpose of the current study was to extend the literature on prompt dependence by comparing interventions for 3 participants with developmental disabilities who consistently engaged in correct responses following prompts but did not perform tasks independently. We compared the efficacy and efficiency of 3 interventions including differential reinforcement, prompt fading, and extended response interval. Intervention results differed across participants, indicating that the most efficacious and efficient intervention for prompt dependence should be individualized via assessment.