Acquisition and generalization of manual signs by hearing-impaired adults with mental retardation

Behavioral procedures have been used to teach manual communication skills to individuals with mental retardation, although few studies have examined the assessment of generalization of such skills beyond the teaching environment. In this study, we investigated the effectiveness of directed rehearsal for teaching and facilitating the generalization of manual signs by six hearing-impaired adults with mental retardation. The effects of directed rehearsal, alone and combined with positive reinforcement for correct responses, were compared to a no-training control condition in an alternating treatments design. Although directed rehearsal was superior to the no-training control condition in teaching manual signs, the procedure was more effective when combined with positive reinforcement. The combined procedure was used to facilitate the generalization of learned signs across a number of variables. The results showed that there were high levels of generalization by all participants across novel phrases, settings, and trainers but variable levels of generalization to another response mode by some subjects. Further, increased levels in overall vocal communication were found for most participants.