The longitudinal study investigated the language acquisition strategies employed over one and one-half years by an eight-year-old autistic child learning sign language. There were specific deviations in language development noted, in spite of providing the child with appropriate sign language training. (Author)

The performance of a 3-year-old with Rett Syndrome in a Contingency Intervention Program using head and hand switches and adapted toys was assessed over 18 months. Learning contingent control of the stimuli positively motivated the child, promoted attention to toys and objects, and generalized to the classroom. (SW)