The z-score statistic that is used in the hypothesis test is the first specific example ofwhat is called a test statistic. The term test statistic simply indicates that the sample dataare converted into a single, specific statistic that is used to test the hypotheses. In thechapters that follow, we introduce several other test statistics that are used in a varietyof different research situations. However, most of the new test statistics have the samebasic structure and serve the same purpose as the z-score. We have already describedthe z-score equation as a formal method for comparing the sample data and the population hypothesis. In this section, we discuss the z-score from two other perspectivesthat may give you a better understanding of hypothesis testing and the role that z-scoresplay in this inferential technique. In each case, keep in mind that the z-score serves asa general model for other test statistics that come in future chapters