Mr. Fenton teaches seventh grade general science at General Arnold middle school. It is Friday afternoon and Mr. Fenton is finishing his instructional unit on the periodic table. As the class ends he assigns twenty questions at the end of Chapter 4 as homework, to be due on Monday. The classroom erupts in complaints and groaning. "It's the weekend," say some students. "The carnival is in town," say others. Feeling sorry for the students' apparent distress, Mr. Fenton reduces the assignment by half. The students' reactions change from complaining, to statements of gratitude for Mr. Fenton's kindness and understanding.

Mr. Fenton completes the next instructional unit the following Friday. After briefly considering assigning twenty questions from the end of Chapter 5, he decides instead to only assign ten questions. Instantly the students begin complaining. This time Mr. Fenton does not reduce the assignment. The students continue to grumble until the period ends and the students leave. In the past, Mr. Fenton has enjoyed teaching this class, but on the following Monday, as the students arrive, Mr. Fenton feels nervous and ill at ease.

1. Define the concept of negative reinforcement and discuss how this concept explains the change in Mr. Fenton's behavior.