Randomization Tests

Randomization tests or permutation tests provide a nonparametric approach based on statistics not requiring that the test statistics have specified distributions. A sampling distribution is obtained by resampling the data to generate a large number of test statistics under a null hypothesis. This chapter illustrates examples of the nonparametric approach including a randomization test for location, a test for correlation, and a test for independence. Permutation tests are also implemented using the boot() function from the boot package. Plots are used to illustrate the resampling distributions of the test statistics.