Abstract

When permutation methods are used in practice, often a limited number of random permutations are used to decrease the computational burden. However, most theoretical literature assumes that the whole permutation group is used, and methods based on random permutations tend to be seen as approximate. There exists a very limited amount of literature on exact testing with random permutations, and only recently a thorough proof of exactness was given. In this paper, we provide an alternative proof, viewing the test as a “conditional Monte Carlo test” as it has been called in the literature. We also provide extensions of the result. Importantly, our results can be used to prove properties of various multiple testing procedures based on random permutations.

Highlights

  • Permutation tests are nonparametric tests that are used in particular when the null hypothesis implies distributional invariance under certain transformations (Fisher 1936; Lehmann and Romano 2005; Ernst et al 2004)

  • Most theoretical literature assumes that the whole permutation group is used, and methods based on random permutations tend to be seen as approximate

  • This paper proves properties of tests with random permutations in a very general setting

Read more

Summary

Introduction

Permutation tests are nonparametric tests that are used in particular when the null hypothesis implies distributional invariance under certain transformations (Fisher 1936; Lehmann and Romano 2005; Ernst et al 2004). Phipson and Smyth (2010) note that adding the identity can make the permutation test exact, i.e. of level α exactly They do not mention the role of the underlying group structure. Instead, they view the permutation test as a Monte Carlo test, which is known to be exact in some situations if the original observation is added. The proof by Phipson and Smyth (2010) is incomplete and it remained unclear what assumptions (e.g. a group structure) are essential for the validity of random permutation tests. 2, we review known results on the level of a permutation test based on a fixed group of transformations.

Basic permutation test
Permutation p values
Random transformations
Comparison of Monte Carlo and permutation tests
Estimated p values
Random permutation tests
Applications
Discussion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call