Establishing evidence- and research-based practices relies upon research synthesis of individual studies in reviews and meta analyses. Further summarizing scientific evidence about a specific topic by synthesizing reviews is an area of need to determine practices that have a strong evidence base and to identify areas of methodological weakness and…

This meta-analysis aimed to evaluate single-case studies that used high-tech speech-generating devices (SGDs) for children with autism spectrum disorders (ASD) ages 0-8. The focus of this review was to measure the effect size of high-tech SGD intervention on verbal behavior. The review included 20 studies with 54 participants with ASD. The results…

Many individuals with autism cannot speak or cannot speak intelligibly. A variety of aided augmentative and alternative communication (AAC) approaches have been investigated. Most of the research on these approaches has been single-case research, with small numbers of participants. The purpose of this investigation was to meta-analyze the single…

Originally designed to enable young children with autism lacking functional communication to initiate requests and to describe what they observed, the Picture Exchange Communication System (PECS) has been the subject of an ever-expanding body of research and development. Thirty-four peer-reviewed published reports on PECS are analyzed in this…