Be definite. Assignments should be spelled out so that students know what they are to do. The amount of guidance required varies with the age and maturity of the students. Any evidences of indecision can serve as the point of entry for misbehavior. Let’s look at three different assignments. “And now you may review for a while.” “I think you need to review the material on gas law problems, so you may work on this for a while.” “During the next ten minutes see how many of the gas law problems you can complete. They are found on page 168 in your book.” Any experienced teacher will see the gradation in this sequence. The first one is an open invitation to “goof off,” with attendant problems. The second is more definite, while the last is even more so. Student response would likely be more positive in the third assignment.