Further evaluation of blocked trials to teach intraverbal responses under complex stimulus control: Effects of criterion-level probes

Individuals with autism spectrum disorder (ASD) often have deficient intraverbal repertoires. Ingvarsson, Kramer, Carp, Petursdottir, and Macias (2016) evaluated the use of a blocked-trial procedure to establish complex stimulus control over the intraverbal behavior of children with ASD. In the current study, we replicated the procedures of Ingvarsson et al. (2016) and added criterion-level probes. Three children with ASD, ages 7-13, participated. We targeted discriminations between questions that differed in subtle ways. The questions were initially presented in trial blocks. Contingent on accuracy criteria the size of the trial blocks was gradually reduced until the questions were presented in quasi-random order. We conducted criterion-level probes (quasi-random presentation) following each step. The blocked-trials procedure was effective with two participants, and probe performance showed that the full set of blocked-trials instructional steps was rarely needed following acquisition of the first discrimination. Hence, the efficiency of the procedure was significantly enhanced for these two participants relative to the previous study. The procedure was not effective for the third participant. These results suggest that the blocked-trials procedure can be an effective and efficient way to teach intraverbals that require conditional discriminations to children with ASD.