Children with autism spectrum disorder (ASD) who have limited spoken communication skills are commonly taught to mand by exchanging picture symbols. Competent manding via symbol exchange relies on conditional discrimination--that is, selecting the picture symbol that corresponds to the desired reinforcer. Picture Exchange Communication System…

In the following paper, two experiments are reported based on the relation between adult approvals as conditioned reinforcers and the number of vocal verbal operants, specifically tacts, mands, wh questions, sequelics, and conversational units emitted by children diagnosed with developmental disabilities. In Experiment I, following an experimental…