Which term describes a reinforcer delivered after a fixed number of responses and not after every response?

• A. Fixed Ratio Reinforcement
• B. Variable Ratio Reinforcement
• C. Fixed Interval Reinforcement
• D. Variable Interval Reinforcement

Answer: (A)

This question is about reinforcement schedules in operant conditioning and asks for a reinforcer that comes after a fixed number of responses rather than after each response. That pattern is fixed ratio reinforcement. Because reinforcement is tied to meeting a set quota, the organism tends to respond vigorously to reach the required number, and after receiving the reward there’s often a brief pause before continuing to the next quota. Think of a punch card: you get a free item after a certain number of purchases, so you keep working toward that fixed target.

If the reinforcement were tied to an unpredictable number of responses, you’d have a variable ratio—a schedule that usually yields a high, steady rate of responding with little to no post-reinforcement pause. If reinforcement depended on time rather than the number of responses, you’d be looking at a fixed interval (reward after a fixed time, with a noticeable pause after delivery and then a pickup in responding as the interval ends). If the timing varied, that would be a variable interval, which tends to produce steady, moderate responding without the pronounced bursts seen in ratio schedules.