Increasing requests by adults with developmental disabilities using incidental teaching by peers.

A peer-delivered incidental-teaching procedure was used to instruct appropriate requesting in adults with moderate to severe mental retardation or autism. Three pairs of group-home residents participated in an incidental-teaching procedure to increase appropriate requesting, prompting, and responding of residents during lunch-preparation sessions. An increase in the number of incidental-teaching episodes during dinner was obtained, and remained high when lunch-making training sessions were withdrawn. In addition, during the incidental-teaching phase, an increase in appropriate requests and overall verbalizations occurred for the peer learners. Changes in appropriate requesting and overall verbalizations also remained higher than baseline when training was withdrawn.