Comparisons of intervention components within augmentative and alternative communication systems for individuals with developmental disabilities: a review of the literature.

Decisions regarding augmentative and alternative communication (AAC) for individuals with developmental disabilities (e.g. what AAC to use and how to teach a person to use a specific AAC modality) should involve consideration of different intervention component options. In an effort to elucidate such decisions and options, this review synthesized 14 studies, published between 2004 and 2012, comparing different AAC intervention components including different symbol sets, instructional strategies, or speech output within aided AAC systems, and different verbal operants within unaided AAC. Evidence supported the following: (a) different instructional strategies such as building motivation, using errorless learning, or adding video models to picture exchange interventions may improve the acquisition or rate of acquisition of picture exchange mands, (b) limited data supports training mimetic (imitated) or mand signs over tacts and (c) differences in symbol sets and speech output levels appeared to have little effect on AAC-based mand acquisition, but listener-based differences should be considered. These findings have implications for future research and clinical practice.