A Variable Interval (VI) schedule of reinforcementReinforcement is a fundamental concept in Applied Behavior Analysis (ABA) and behavioral psychology. It refers to any consequence that follows a behavior and increases the likelihood that the behavior... More delivers reinforcement for a behaviorBehavior refers to any activity or action that living organisms engage in, which can be observed, measured, and analyzed. It encompasses all interactions an organism has with its environment, inc... More after an unpredictable amount of time has passed, but the intervals average out over time. The learner doesn’t know exactly when the next reinforcement will occur, which encourages consistent responding because reinforcement could happen at any moment.
Example
A teacher praises a student for staying on-task, but the praise is delivered at unpredictable intervals, such as after 5 minutes, 12 minutes, and then 8 minutes, averaging out to a 10-minute interval. The student is more likely to stay on-task consistently because they don’t know when the next praise (reinforcement) will happen.