Meta-analysis of noncontingent reinforcement effects on problem behavior.

A meta-analysis of noncontingent reinforcement (NCR) outcomes was conducted using hierarchical linear modeling (a) to document the effect size for decreasing problem behavior, (b) to compare effect sizes for NCR using functional reinforcers and nonfunctional reinforcers, and (c) to document the influence of schedule thinning on effect size. Analyses were conducted with data from 55 studies and 91 participants. Results indicate that NCR was associated with a very strong effect size (d =-1.58) for reduction of problem behavior, functional reinforcers were slightly more effective than nonfunctional reinforcers, and schedule thinning resulted in minor degradation of effect size. Meta-analysis of single-case design data provides a method to quantitatively estimate effect sizes of interventions across participants. Therefore, it allows one to identify important variables that are not otherwise evident in single-case data, helps to disseminate findings to the broader scientific community, and contributes to the documentation of empirically supported interventions.