Which schedule rewards after a fixed period of time has elapsed?

• A. Fixed Interval Reward Schedule
• B. Variable Interval Reward Schedule
• C. Continuous Reward Schedule
• D. Fixed Ratio Reward Schedule

Answer: (A)

In a fixed interval schedule, reinforcement is delivered after a specific, set amount of time has elapsed since the last reward, regardless of how many responses occur in that interval. That time-based condition is what defines this schedule, so rewards become available only after the fixed interval has passed. As a result, responses tend to be low right after a reward and increase as the interval nears its end, creating a scalloped pattern of responding.

This aligns with the description of rewards occurring after a fixed period of time has elapsed.

Other schedules don’t fit because:

• Variable interval gives rewards after unpredictable time intervals, not a fixed one.

• Continuous reinforcement delivers a reward after every correct response, not after a fixed time.

• Fixed ratio provides a reward after a set number of responses, regardless of time.