Which schedule of reinforcement provides rewards after varying amounts of time and reinforces a behavior occasionally?

The correct answer is the variable interval schedule. This type of reinforcement schedule provides rewards after varying amounts of time have passed, meaning that the reinforcement is delivered at unpredictable time intervals. This unpredictability creates a strong and steady rate of behavior because individuals become persistent in their actions in anticipation of the reward, even though they may not know when it will come.

For example, if a worker knows they will receive a paycheck on a variable interval schedule, they might perform their duties consistently, even if they are unsure exactly when the paycheck will arrive. The key characteristic of this schedule is that the reinforcement is not linked to a specific number of responses or actions (like a fixed ratio) or delivered consistently after every response (as in continuous reinforcement). Instead, it is reliant on an unpredictable timeframe, which helps to maintain engagement and motivation over a longer period.