“…The communicative environments of children with intellectual disabilities can greatly differ from those of children with typical development (Cardoso-Martins, Mervis, & Mervis, 1985;Ruskin, Kasari, Mundy, & Sigman, 1994); although it should be more contingent and responsive to the child's lead, often it is more directive and adult-guided (Light, Collier, & Parnes, 1985a, 1985bMahoney & Wheeden, 1999). Parents often adapt their language and communication to the expressive language level of the child, but this may result in less diverse and complex talk that does not necessarily provide the optimal environment in which to stimulate communication and language development (Kaiser et al, 2001). Expansion of children's utterances (more complex vocabulary, greater information, and/or more complete syntax) in concrete rich contexts can optimize language learning and communicative competence of children requiring intervention (Kaiser, Hancock, & Hester, 1998;Romski, Sevcik & Adamson, 1999).…”