What is a key feature of a variable-interval schedule of reinforcement?

A key feature of a variable-interval schedule of reinforcement is that reinforcement follows a random time schedule. This means that the timing of reinforcements is unpredictable, leading to a steady and high rate of responding. Because individuals do not know when the next reinforcement will be available, they are motivated to continue the behavior consistently over time, as they may receive reinforcement at varying intervals.

In this context, the unpredictability enhances engagement since the individual must keep responding to increase the likelihood of receiving reinforcement. This contrasts with schedules like fixed-interval, where reinforcement is delivered after a set amount of time, creating clear patterns in behavior. Similarly, other schedules like continuous reinforcement or fixed-ratio, where reinforcement depends on specific responses or behaviors, do not embody the randomness characteristic of a variable-interval schedule.