You don’t have to know everything in this chapter, but many topics introduced here will help you if cannot afford an evaluator or statistician. What is presented below leans toward the ideal. You will not hit every mark. There is no harm in striving for perfection, though, because usually everyone fails to hit the 100% mark. For example, if you strive for an A and receive a B, then B is OK, because you did your best. Otherwise, you might have received a much lower grade. This analogy fits this chapter very well.