Systematic Review of Variables Related to Instruction in Augmentative and Alternative Communication Implementation: Group and Single-Case Design.

Purpose: This article provides a systematic review and analysis of group and single-case studies addressing augmentative and alternative communication (AAC) intervention with school-aged persons having autism spectrum disorder (ASD) and/or intellectual/developmental disabilities resulting in complex communication needs (CCNs). Specifically, we examined participant characteristics in group-design studies reporting AAC intervention outcomes and how these compared to those reported in single-case experimental designs (SCEDs). In addition, we compared the status of intervention features reported in group and SCED studies with respect to instructional strategies utilized.