Assignment task:
Mary wants some attention from her teacher but the only time her teacher attends to her is when she does something the teacher doesn't like. Each time Mary calls out in class or gets out of her seat without permission, her teacher scolds her (e.g "Mary be quiet" or "Mary, sit down"). The immediate effect is that Mary stops doing whatever it is her teacher doesn't like, but this doesn't last for long. Eventually, she calls out or gets out of her seat again. Mary's teacher continues to scold her.