The general purpose of the current study was to evaluate the potency of different categories of reinforcers with young children diagnosed with developmental delays. The participants were two boys and one girl who were between the ages of seven and eight. In Phase 1, we evaluated the reinforcing potency of tokens, edible items, and leisure items by using a progressive ratio (PR) schedule. For two participants, we found that tokens resulted in the highest PR break points. For one participant, edibles resulted in the highest break points (tokens were found to have the lowest break points). In Phase 2, we evaluated the effects of presession access on the break points of edibles and tokens. This manipulation served as a preliminary analysis of the extent to which tokens might function as generalized conditioned reinforcers. During Phase 2, presession access altered the break points of edibles, but not tokens. The findings of the current study suggest that PR schedules may be useful as a means to better assess certain dimensions of tasks and how they affect reinforcer effectiveness (e.g., amount of effort the client is willing to exert, the duration at which the client willing to work, how many responses the client will emit, etc.), and to evaluate to what extent tokens actually function as generalized conditioned reinforcers.

Reinforcer assessments have largely relied on the use of progressive ratio (PR) schedules to identify stimuli that function as reinforcers. PR schedules evaluate the reinforcing efficacy of a stimulus by measuring the number of responses produced in order to access a stimulus as the number of required responses increases. The current evaluation extends the literature on reinforcer assessments by measuring responding under a progressive force (PF) schedule, in addition to progressive ratio requirements. We compared responding under PR and PF schedules with two children with autism using a multielement design embedded within a reversal experimental design. Results were mixed and implications for further development of reinforcer assessment methods (particularly PF schedules) are discussed.