This chapter discusses nonparametric statistical tests that make fewer assumptions about the underlying data distribution, including the sign test, Wilcoxon signed-rank test, and Mann-Whitney U-test. It provides examples of how to conduct each test and interpret the results. The sign test can test for differences in paired samples or a single population median. The Wilcoxon signed-rank test incorporates information about the magnitude of differences between paired samples. The Mann-Whitney U-test compares two independent samples and tests whether their population medians are the same.