Experimental Design

A single subject adapted alternating treatments design (AATD; Sindelar, Rosenberg, & Wilson, 1985) was used to evaluate the effects of the IVs on the selected DVs for the purposes of this study. The reason for the selection of this research design lied in that the ATDD allows for the comparison of the effect of training interventions (non-reversible behaviors) on paraeducator performance (Ledford & Gast, 2018). Counterbalancing of IV-target skill combinations was conducted across the three paraeducator participants in this study in order to minimize potential threats to internal validity (e.g., sequence effects). For example, Elizabeth was trained to teach tacts of pictures of common stimuli using BST, listener responding of actions using BPF and intraverbal targets using typed instructions (i.e., control measure) Similarly, Mary was trained to teach listener responding of actions using BST, intraverbal targets using BPF and tact of pictures of common items using typed instructions (i.e., control measure). Lastly, Caroline was trained to teach intraverbal targets using BST, tact of pictures of common items using BPF, and listener responding of actions using typed instructions (i.e., control measure; see Table 3 for details regarding counterbalancing of IV/target skill combinations). In addition, during the study, treatment interference effects were minimized by attempting to increase, to the greatest possible

extent, the amount of time between delivery of each training strategy, (Ledford & Gast, 2018). For example, each strategy presentation for participant one occurred after at least thirty minutes of delivery of the previous training strategy. Moreover, potential effects of time of the day intervention delivery were counterbalanced by alternating the presentation of interventions within and across observation days (e.g., BPF presentation in the morning of day one and in the afternoon on day two; see Table 4 for details regarding schedule of intervention delivery). Participants introduction to the intervention condition was based on low level, stable performance during the baseline condition with respect to the frequency of correct errorless teaching sequences performed by paraeducators (Johnston & Pennypacker, 2008). Training was terminated for participants after teaching at least ten correct errorless teaching sequences, across the five targets selected for acquisition, in each verbal skill taught (i.e., tact, listener responding, and intraverbal) with no errors for three consecutive observation days (100% implementation fidelity; Ledford & Gast, 2018). It is worth noting that if one of the training strategies evaluated (i.e., BFP or BST) met training termination before the other, the less effective training strategy continued to run for 1.5 the number of sessions it took the more effective strategy to meet training termination. If the less effective training strategy reach termination within the established additional number of sessions, then the training was discontinued. If training termination was not met after the established additional number of sessions, then training was then discontinued (Ledford & Gast, 2018). During this time, data was also collected consistently on the training strategy assigned to the control condition (i.e., typed instructions) until the training for the other strategies was discontinued (Ledford & Gast, 2018).

Table 3. Counterbalancing IV/target skill combinations

3.1.5.1 Task equivalence.

Consistent with the logic of the single subject research AATD (Sindelar et al., 1985), the difficulty of implementation of the errorless teaching sequences to teach target skills (i.e., tacts, listener responding, and intraverbal skills) as well as the difficulty in the teaching and performance of each target skill was evaluated to ensure that behavior chains/sets taught by paraprofessional participants are functionally similar, independent, and of equal difficulty (Ledford & Gast, 2018). With respect to the errorless teaching sequence to teach target tacts, listener responding, and intraverbals, an analysis of each sequence was conducted in terms of the number of steps (all sequences consisted of six steps) and the paraprofessionals’ responses associated with each step of the sequence (e.g., the use of echoic prompt to teach tact; the use of imitation prompts to teach listener responding). In addition, opinions of two Board Certified Behavior Analysts-Doctoral level (BCBA-D) and one senior, masters level Board Certified Behavior Analyst (BCBA) were obtained. All three were experts in the application of behavioral principles as well as the design and delivery of language training interventions based on Skinner’s analysis of verbal behavior (Skinner, 1957). Their opinions were obtained regarding the equivalence of each of the errorless teaching sequences, particularly the function of each sequence, number of adults required, number of steps in each sequence, and an overall assessment of the difficulty and equivalence of each errorless teaching sequence. All experts (100%) agreed that the function of the errorless teaching sequence was instructional in nature. In addition, all experts (100%) agreed that all targeted sequences included the same number of steps and did not involve additional individuals to be implemented. Two of the experts (67%) did not find meaningful differences across the three errorless teaching sequences, while one of the experts did (e.g., type of prompt use to teach specific verbal skills). Overall, no expert considered one errorless teaching sequence to be more difficult

to implement than the others. Similarly, with respect to the target verbal skills taught by paraprofessionals (i.e., tact, listener responding, and intraverbal), all experts agreed that each of the target skills to be taught by paraprofessionals to be basic verbal operants that do not require multiple verbal conditional discriminations. In addition, experts agreed on the equivalence of each target skill if taught as a basic verbal operant, not requiring multiple verbal responses or responses that involve multiple conditional discriminations. See Table 5 for details regarding experts’ task equivalence assessment.