Locke & Latham (2002) have found that goal difficulty and goal specificity are important factors in successful goal-setting behaviors. Performance tends to decrease when goal difficulty is extremely low or extremely high (past a certain difficulty threshold), and when goals are unclear and unspecific. Performance tends to increase when goals are specific and clear. They have also noted that, “Goals have an energizing function.” That is to say that when goals are more challenging work effort increases. Thus, students may be more willing to put more work into a more challenging goal early on than a less challenging goal. The confounding variable here, however, is that perhaps more challenging goals also require more work to complete, thus it is less likely that students can afford to procrastinate them as drastically as less challenging goals.