Intraverbal behavior, in which an antecedent verbal stimulus is followed by a verbal response that lacks point-to-point correspondence with that stimulus, is often lacking in mentally retarded individuals. The present studies examine the use of transfer of stimulus control procedures for developing one type of intraverbal responding (classification of verbal responses) in mentally retarded participants who employed manual signs as their primary mode of verbal communication. In Experiment 1, a delayed prompting procedure was used to transfer control from nonverbal stimuli (pictures) to verbal stimuli (signs). This procedure was modified so that transfer of stimulus control was effected without errors in Experiment 2. In Experiment 3, a delayed prompting procedure was employed to train intraverbal behavior that involved a conditional discrimination. In all cases, transfer of stimulus control procedures produced rapid and enduring improvement in participants' intraverbal responding.
