Development of communicative behavior in autistic children: a parent program using manual signs.

Mothers of four 6- and 7-year-old autistic classmates were taught to use manual signs for verbalizations to aid development of appropriate communicative behavior and to deter undesirable behavior in their children. The experimental treatment was initiated in a daily mother-child laboratory session using a multiple-baseline design across subjects. The preschool classroom program remained unchanged. Data were recorded for each child daily over a 5-week period, in the classroom and in a mother-child session, on four types of communicative behavior and four types of inappropriate behavior. Communicative behaviors increased and inappropriate behaviors decreased in relation to baseline conditions for each child. The manual sign program facilitated generalization of communicative behavior to the child's total environment. Desirable behaviors were maintained and had improved in the classroom 3 months after initiation of the program.