Which schedule of reinforcement provides reinforcement at the end of a predetermined interval contingent on emitting fewer than a gradually decreasing criterion of responses?

• A. DRL
• B. DRH
• C. FR
• D. DRD

Answer: (D)

The concept here is shaping by progressively reducing how often a behavior occurs. In a diminishing rates schedule, you set an interval and a criterion for the number of responses within that interval. At the end of the interval, reinforcement is provided only if the observable number of responses is fewer than the current criterion, and that criterion is gradually lowered over time. This creates a progressive tightening that lowers the overall response rate.

This matches the description because the reinforcement depends on emitting fewer than a gradually decreasing number of responses within a set interval. If you were dealing with longer gaps between responses to get reinforcement, that would be a DRL setup; if reinforcement depended on achieving a fixed number of responses, that would be FR; and if reinforcement required a high rate of responding, that would be DRH. So the schedule described is Differential Reinforcement of Diminishing Rates.