The Effects of Lag 3 Schedules and Interresponse Intervals on the Variability of Responding in Individuals with Autism

In the present study, a changing-criterion experimental design was employed to demonstrate the effects of a lag schedule of reinforcement and various interresponse intervals (IRI) on the response variability of three individuals with autism. The results showed that variable responding increased for one participant after introduction of the lag schedule of reinforcement, it remained variable with the introduction of 5-s IRI, and it was maintained for an eight-week period after the lag-3 schedule was withdrawn. Results for the other two participants showed that varied responses increased partially. These results are discussed in terms of lag schedules of reinforcement and various IRIs that support variable responding, the conditions that can promote maintenance of such responding, and the stimulus control of varied responding