Background: Interventions for augmentative and alternative communication (AAC) have been employed for people with development disabilities, who have a severe speech and language impairment. Comparing the effects of various intervention strategies would help practitioners select an appropriate intervention among multiple options.
Objectives: To conduct a narrative review of single-subject studies on the effects of AAC intervention for individuals with developmental disabilities.
Search strategy: The studies were found through conducting reference checks for previous studies on ACC as well as using the following databases: CINAHL, ERIC, MEDLINE, and PsychINFO.
Selection criteria: Studies that meet the following criteria were included: (a) the study compared the effectiveness or efficacy of at least two ACC interventions by employing a comparative single-subject experimental design; (b) the purpose of the intervention compensated the impairment and disability patterns of individuals with severe expressive communication disorders; (c) participants of the intervention had a developmental disability; and (d) the study was published in English in a peer-reviewed journal, as a book chapter, or as a dissertation.
Data collection and analysis: Selected studies were reviewed and categorized by author(s), purpose of study, participants, design, results, and evaluation of evidence. Evaluation of evidence was conducted according to several methodological criteria (e.g., whether teaching criterion was set).
Main results: The authors reported the results in three categories: (1) studies involving unaided approaches (23 studies), (2) studies involving aided approaches (20 studies), and (3) studies involving both aided and unaided approaches (7 studies).
Conclusions: Practitioners would be able utilize the comparisons of studies, evidence appraisal, and recommendations for intervention selection to select the appropriate intervention.