Teaching a Multihandicapped Adult Manual Signs Using a Constant Time Delay Procedure

A 31-year-old severely hearing impaired young man, with mild to moderate retardation and cerebral palsy, was taught to sign labels manually for six photographs of people, places, and objects found in his work environment. A constant 4-second time delay procedure was used as well as a multiple probe design across manual signs. Generalization probes were conducted: (1) to measure the extent to which the worker could successfully comprehend these same signs after expressive sign training, although no direct receptive sign training was provided and (2) to test whether he could identify actual people, places, and objects in his work environment. The worker learned to produce all six manual signs in near-errorless fashion. In addition, after reaching criterion on sign production, he was able (1) to label actual people, places, and objects found in his work environment and (2) to comprehend these same signs. The constant time delay transfer of stimulus control procedure proved to be both an effective and efficient instructional method.