A Systematic Review of Augmented Input Interventions and Exploratory Analysis of Moderators

Purpose Augmented input is the act of concurrently modeling language verbally and on a communication device, and is one strategy for teaching individuals to effectively use aided modes of communication. The purpose of this literature review is to assess the efficacy of augmented input for increasing communication and to identify intervention components, participant characteristics, and instructional contexts related to therapeutic outcomes. Method We double screened all potential sources and double coded all included sources. Database, forward, and backward searches yielded 99 single case designs in 26 sources. We coded characteristics of participants, instructional contexts, independent variables, and dependent variables. We also coded quality/rigor and primary outcomes for each design or comparison. Results Across high-quality studies, two thirds of designs indicated that augmented input was effective compared to baseline conditions and alternative interventions, and exploratory analyses indicated that receptive language skills, age, and diagnoses may moderate intervention efficacy. Most augmented input interventions included additional components that may serve as "active ingredients" (e.g., systematic prompting, contextual reinforcement). Most studies also did not report participant characteristics hypothesized to moderate intervention efficacy (e.g., joint attention skills, imitation repertoire). Results also indicated high risk of publication bias, with peer-reviewed sources twice as likely to include positive effects than dissertations and theses. Conclusions Across high-quality studies, augmented input was inconsistently effective as a stand-alone intervention. Packaged interventions that included augmented input were typically more effective than augmented input in isolation, particularly for individuals who were young, had strong receptive language skills, or had no comorbid diagnoses.