“…For children with developmental disabilities to learn to gain access to desired items appropriately, communicate their needs and desires, request information, obtain others' attention, and generally control their environments, it is important that they acquire a functional form of communication (McCoy & Buckhalt, 1990). In addition, development of functional communication skills has also been shown to reduce problem behavior by individuals with developmental disabilities (Carr & Durand, 1985;Richman, Wacker, & Winborn, 2001;Winborn, Wacker, Richman, Asmus, & Geier, 2002).…”