Experimental control in the adapted alternating treatments design: A review of procedures and outcomes

Abstract

The adapted alternating treatments design (AATD) is a single‐case experimental design (SCD) that allows for the comparison of two or more instructional procedures on the acquisition of non‐reversible behaviors. Recent descriptions of quality indicators and methodological practices (e.g., equating target sets) specific to the AATD may help guide researchers and clinicians interested in using this design, although additional descriptions of best practices are warranted. One area that has not been considered previously are methods to demonstrate experimental control in the AATD; a two‐step process that involves experimental procedures and outcomes of the study. The current review analyzed studies published using the AATD in 27 journals to describe researchers' use of methods that allow for the demonstration of experimental control (e.g., no‐treatment control condition or combined experimental designs) and, when present, whether participants' responding suggested that potential threats to internal validity were present. The current review found that authors arranged for some type of control procedure in just over half of the reviewed studies. These studies also commonly adhered to recommended practices by frequently assessing responding in the control condition; nevertheless, participant performance suggesting potential threats to internal validity were common. Recommended practices and areas for future research are considered.

Comparison of mastery criteria applied to individual targets and stimulus sets on acquisition of tacts, intraverbals, and listener responses

“…An adapted alternating treatments design (Cariveau & Fetzner, 2022; Sindelar et al, 1985) was used to compare the effects of an individual target versus set mastery criterion on acquisition. Sessions of each condition were alternated until all assigned stimuli were mastered in one condition.…”

Comparing a modified simple‐conditional with the conditional‐only methods in teaching Chinese children with autism

“…Second, even though we combined the adapted alternating treatments design with a multiple‐probe design, certain threats to internal validity, such as multiple‐treatment interference and history effects, may not be detected when the design is staggered across participants (Cariveau & Fetzner, 2022). Including a no‐treatment control with adapted alternating treatments design or embedding the comparisons in a multiple‐baseline or multiple‐probe design across stimulus sets—instead of participants—could provide control for these threats.…”

“…Third, although we included multiple participants, we conducted one comparison per participant and thus could not evaluate intrasubject replication. Arranging for inter‐ and intrasubject replications may be important for analyses of internal, external, and predictive validities of the comparisons (Cariveau & Fetzner, 2022; Kodak & Halbur, 2021).…”

Teaching children with autism spectrum disorder to tact auditory stimuli: A replication

“…We did not replicate the mixed-trials procedure used in Hanney et al (i.e., the experimenter alternates between auditory tacts and visual tacts within the same session) when Jude did not respond correctly to the isolated tacts when presented with corresponding visual stimuli in the stimulus-control post-training probes. Because we used a multiple probe design across sets to enhance experimental control (Cariveau & Fetzner, 2022), we did not want to alter the training history before exposing Jude to the isolated and compound conditions with the second set of stimuli. We intended to return to the set 1 stimuli following training with set 2, but Jude transitioned to a kindergarten classroom before that could be conducted.…”

“…In addition, Patrick and Jude both emitted correct responses in the stimulus‐control probes when presented with some of the visual stimuli that were assigned to the compound‐with‐unknown condition. These responses are a threat to internal validity and may suggest issues with multiple‐treatment interference (i.e., carryover effects), repeated testing, and maturation (Cariveau & Fetzner, 2022). We did not assess visual tacts throughout the intervention, so this was not detected until post‐intervention probes.…”