Justin often attempts to jump off classroom chairs. his teacher decided to reduce the behavior by having him repeatedly jump off the classroom chair, while under close supervision. this is an example of

Based on the description, the teacher's approach is an example of: negative practice
Negative practice is an effort to introduce negative effect to a specific action in order to make a person discouraged from doing it. By making justin jump of the chair over and over again, he wll associated the activity with physical distress and make him discouraged from doing it again in the future