- Permutation tests, also called randomization tests, re-randomization tests, or exact tests
- Type of statistical significance test in which the distribution of the test statistic under the null hypothesis is obtained by calculating all possible values of the test statistic under rearrangements of the labels on the observed data points
- In other words, the method by which treatments are allocated to subjects in an experimental design is mirrored in the analysis of that design
- If the labels are exchangeable under the null hypothesis, then the resulting tests yield exact significance levels