A comparison of single-case evaluation tools applied to functional communication training with augmentative and alternative communication supports for students with developmental disabilities

Background: Students with developmental disabilities frequently present with both limited vocal speech and challenging behavior. Functional communication training (FCT) with augmentative and alternative communication (AAC) supports, is a commonly recommended intervention to reduce challenging behavior for these students, while also increasing appropriate communication. Aims: Current research on this topic has not applied multiple evaluation tools, despite the recent suggestion to do so. Further, there are limited studies in the field of special education that have (a) applied multiple evaluation tools and (b) compared the results of the tools. Method: In the current review, we applied three evaluation tools to intervention studies examining the use of FCT with AAC supports in school-based settings to determine the current level of scientific support for this intervention. We identified 38 studies, which contained 59 single-case designs (SCDs). Next, we compared the methodological rigor and/or quality, outcome scores, and Evidence-Based Practice (EBP) ratings provided by the three evaluation tools. Results and conclusion: Our results yielded inconsistent methodological rigor and/or quality, participant outcome measures, and EBP classifications between the evaluation tools. No two evaluation tools completely aligned. Limitations and future research are discussed.