In a Variable Interval Schedule, how is reinforcement scheduled?

In a Variable Interval Schedule, reinforcement is delivered after a variable amount of time has elapsed. This means that the time between reinforcements fluctuates, making it unpredictable for the learner when the next reinforcement will occur. This unpredictability encourages consistent responding because the individual learns that they may be rewarded at any time, but the exact timing is uncertain.

This schedule is particularly effective in maintaining steady behavior since the individual must continue engaging in the desired behavior throughout the interval in anticipation of a potential reward, even though the exact timing of the reinforcement varies. It contrasts with fixed schedules where the timing or number of responses required for reinforcement is predictable and consistent.