Final answer:
The fixed interval reinforcement schedule is associated with a low-to-moderate rate of responding, characterized by a scallop-shaped pattern of responses due to reinforcements being provided after set periods of time, regardless of the number of responses.
Step-by-step explanation:
A schedule of reinforcement that produces a low-to-moderate rate of responding is known as the fixed interval reinforcement schedule. In this type of schedule, reinforcement is provided after a set amount of time has passed, regardless of the number of responses made. For example, if someone is on a fixed interval schedule for receiving pain relief medication after surgery, they receive the medication at set times, not based on how many times they request it. This schedule tends to produce a scallop-shaped pattern of response rates, where there is a period of inactivity after reinforcement, followed by an increase in response as the time for the next reinforcement approaches. In contrast, a variable ratio reinforcement schedule involves reinforcement after an unpredictable number of responses and tends to yield high and steady response rates. It is the most powerful among the partial reinforcement schedules and is highly resistant to extinction. Therefore, the variable ratio schedule is not associated with a low-to-moderate rate of responding but instead with a high level of responding.