A common practice in tact training is to include a supplemental verbal stimulus (e.g., "What is it?") in addition to the presentation of a nonverbal discriminative stimulus. Previous literature has suggested that this supplemental verbal stimulus can impede acquisition and generalization relative to the presentation of the object alone, as it may establish faulty stimulus control or decrease spontaneous tacting. Research has yet to compare these 2 training methods on the generalization of learned tacts to more naturalistic, play-based environments. The present study evaluated the use of "What is it?" compared to the presentation of only the nonverbal discriminative stimulus on tact acquisition among 3 children with autism spectrum disorder and the extent to which these training procedures led to tacting in a play-based setting following discrete-trial training. Overall, participants learned to tact stimuli under both conditions, and all participants demonstrated generalization of tacts in a play-based setting. Recommendations for the development and evaluation of naturalistic posttraining assessment are discussed.
