Optimal sample size planning for the Wilcoxon-Mann-Whitney test.

ABSTRACT: There are many different proposed procedures for sample size planning for the Wilcoxon-Mann-Whitney test at given type-I and type-II error rates α and β, respectively. Most methods assume very specific models or types of data to simplify calculations (eg, ordered categorical or metric data, location shift alternatives, etc). We present a unified approach that covers metric data with and without ties, count data, ordered categorical data, and even dichotomous data. For that, we calculate the unknown theoretical quantities such as the variances under the null and relevant alternative hypothesis by considering the following "synthetic data" approach. We evaluate data whose empirical distribution functions match the theoretical distribution functions involved in the computations of the unknown

SUBMITTER: Happ M 

PROVIDER: S-EPMC6491996 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature