Evaluation of a Treatment Package to Increase Mean Length of Utterances for Children with Autism

Skinner's (1957) classification of mand responses has spawned decades of research related to teaching individuals with developmental disabilities. However, few studies have evaluated how to teach individuals with autism to progress from simple to more complex mands for desired items and activities. The present study used a treatment package consisting of errorless teaching, differential reinforcement, and systematic decision rules to increase the number of words per mand utterance used by 6 children with autism. Daily probes were conducted in the absence of prompting and differential reinforcement throughout every stage of the treatment. Results showed that all children showed significant developmental gains in the mean length of utterances. Increased rates of manding, increased emission of mand frames, and decreased instances of indicating responses (i.e., pointing, reaching) in the absence of mands were also observed. Implications regarding the feasibility of intensive mand training in practice are discussed.