12. Nonparametric Statistics University of （12。）.pdf

12. Nonparametric Statistics Objectives Calculate Mann-Whitney Test Calculate Wilcoxon’s Matched-Pairs Signed-Ranks Test Calculate Kruskal-Wallis One-Way ANOVA Calculate Friedman’s Rank Test for k Correlated Samples Nonparametric statistics or distribution-free tests are those that do not rely on parameter estimates or precise assumptions about the distributions of variables. In this chapter we will learn how to use SPSS Nonparametric statistics to compare 2 independent groups, 2 paired samples, k independent groups, and k related samples. Mann-Whitney Test Let’s begin by comparing 2 independent groups using the Mann-Whitney Test. We’ll use the example presented in Table 20.1 in the textbook. We want to compare the number of stressful life events reported by cardiac patients and orthopedic patients. Open stressful events.sav. Select Analyze/Nonparametric Tests/Two Independent Samples. Select data as the Test Variable and group as the Grouping Variable. Click on Define Groups and specify 1 for Group 1 and 2 for Group 2, then click Continue. Under Test- Type, select Mann-Whitney U. Then click on Options. Under Statistics, select Descriptives. Then click Continue. In the main