Though sometimes it's a little early or a little late, your mail almost always arrives around 10:30 in the morning. As it gets closer to 10:30, you tend to check the mailbox more often. This is an everyday example of a variable-interval schedule of reinforcement.

Question

Quizplus · Accepted Answer

This is an example of a variable-interval schedule of reinforcement, as the reinforcement (the arrival of the mail) occurs at varying intervals of time, but consistently around 10:30 in the morning. The checking of the mailbox is the behavior that is being reinforced.

Though Sometimes It's a Little Early or a Little Late