A training program, using dual trainers, was used to reduce inappropriate verbalizations and increase appropriate verbal responses of three profoundly handicapped individuals. During training, one trainer asked questions and the other trainer gave verbal prompts. The method was evaluated with three experiments: Experiment I used dual trainers with three Ss with communication problems; Experiment II used dual trainers--one professional and one paraprofessional; and Experiment III compared a dual trainer condition with a single trainer condition. Results of all three experiments demonstrated the validity of the dual training condition. Justification for the use of dual trainers is presented along three dimensions: facilitation of training, control of problem behaviors, and teacher training. (Author)