What schedule delivers the reinforcer after a varying number of responses around an average value?

The schedule that delivers the reinforcer after a varying number of responses around an average value is the variable ratio schedule. This type of reinforcement schedule is characterized by the fact that the number of responses required to receive reinforcement fluctuates, but it averages out to a set number across numerous trials. For example, a person might win a prize after 3 responses on one occasion, 7 responses the next time, and 5 responses after that, with the average being around 5.

This variability creates a high rate of responding because individuals are often unsure when the next reinforcer will come, leading them to respond more frequently and persistently. This unpredictability contributes to the robustness of the behavior being reinforced, making the variable ratio schedule particularly effective in producing persistent behavior.

In contrast, fixed ratio schedules deliver reinforcement after a set number of responses, fixed interval schedules do so after a set period, and intermittent schedules generally refer to a broader category that includes both fixed and variable schedules. Understanding the nuances of these distinctions is essential for applying behavioral principles effectively.