Which schedule of reinforcement yields reinforcement after a fixed number of responses?

• A. Fixed-Interval Schedule
• B. Fixed-Ratio Schedule
• C. Variable-Interval Schedule
• D. Variable-Ratio Schedule

Answer: (B)

Reinforcement contingent on a set number of responses is being described. In a fixed-ratio schedule, reinforcement occurs after a specific, unchanging number of responses. The “fixed” means the required count doesn’t vary, and the “ratio” refers to how many responses must occur before the reward. For example, getting paid after producing five items illustrates a fixed-ratio arrangement. Because rewards are tied to a concrete count, the rate of responding is typically high, often with a brief post-reinforcement pause before the next burst of activity begins.

This differs from a fixed-interval schedule, where reinforcement depends on time rather than a response count; from a variable-ratio schedule, where the number of responses needed for reinforcement varies unpredictably; and from a variable-interval schedule, where reinforcement is delivered at unpredictable times. The description fits a fixed-ratio schedule.