Removal of current or future unpleasant consequences to increase the likelihood that someone will repeat a behavior is called negative reinforcement.
Negative reinforcement is a technique for teaching specific behaviors. In response to a stimulus, something unpleasant or uncomfortable is taken away with negative reinforcement. With the expectation that the unpleasant thing will be removed, the target behavior should increase over time.
One of the most effective forms of negative reinforcement in schools could be the removal of homework in response to excellent work ethic. If a child works exceptionally hard in school one day and goes above and beyond, an appropriate response would be to give that child a night off from homework.