Assessing the acquisition of requesting a variety of preferred items using different speech generating device formats for children with autism spectrum disorder

Five children with autism spectrum disorder (ASD) were taught to request preferred items using four different augmentative and alternative communication (AAC) displays on an iPad (R)-based speech-generating device (SGD). Acquisition was compared using multi-element designs. Displays included a symbol-based grid, a photo image with embedded hotspots, a hybrid (photo image with embedded hotspots and symbols), and a pop-up symbol grid. Three participants mastered requesting items from a field of four with at least three displays, and one mastered requesting items in a field of two. The fifth participant did not acquire requests in a field of preferred items. Individualized display effects were present, and the photo image appeared to have provided the most consistent advantages for three participants. Some errors were more or less common with specific displays and/or participants. The results have important implications for AAC assessment and implementation protocols.