Variant and invariant high-probability requests: increasing appropriate behaviors in children with emotional-behavioral disorders.

This study examined the effects of variant versus invariant high-probability (high-p) request sequences on the performance of requests to initiate a social bid by young children with emotional-behavioral disorders. In the initial phases of the investigation, a multiple baseline design showed that the delivery of invariant sequences (i.e., high-p requests delivered in the same sequence) produced initial increases in compliance to requests to initiate a social bid to a peer. However, increases were not maintained across the invariant condition. The delivery of variant high-p sequences produced increases in compliance to requests to initiate social bids that were maintained across the variant condition. In a follow-up condition, the number of requests within the pool of the variant and invariant high-p requests were controlled. Results of the follow-up condition replicated those found in the initial condition. Implications for applied use and future research are discussed.