The purpose of this investigation was to examine the evocative- and abative-effects of a functionally defined motivating operation (MO) on the frequency of a target behavior maintained by primary, conditioned, and token reinforcers. Furthermore, this investigation sought to determine if the classes of reinforcers were differentially influenced by MOs. A comprehensive literature review and an empirical study were conducted to address the aforementioned research questions.
An electronic search of the literature on MOs yielded 25 articles that met all of the inclusionary criteria. Articles were evaluated using an 11-item matrix. The effects of MOs were examined within and across the reinforcer classes. Serious procedural limitations were found in a majority of the articles. About one-third of the MO manipulations for primary and conditioned reinforcers produced positive results. The total number of MO manipulations for token reinforcers were too few to meaningfully compare the relative effectiveness. The results of the literature review were inconclusive with respect to documenting differential effects of an MO. The implications of these findings as well as guidelines for future research are discussed.
The interaction effects between MO and reinforcer class were evaluated using a superordinate multielement design with an initial baseline. Two teens with developmental disabilities and one typically developing young child participated in this study. Reinforcers were delivered according to a progressive ratio schedule of reinforcement. The results suggest that the effectiveness of each reinforcer class was influenced by changes in motivation. Furthermore, differential effects were evident for two of the three participants. These results are discussed as they relate to the advancement of MO theory, implications for practice, and directions for future research.