Fixed Interval Schedule

A fixed interval schedule is a method of reinforcement where a reward is given after a specified, consistent amount of time has passed, as long as the desired behavior occurs at least once during that period. For example, if a worker receives a paycheck every two weeks, that's a fixed interval schedule. In behavioral terms, the opportunity for reinforcement is predictable, and the behavior tends to increase as the time approaches the scheduled interval, often leading to a "scalloped" pattern of activity—less activity immediately after reinforcement and more as the time nears the next scheduled reward.