title: Wilcoxon test after Levene's transformation can have an inflated Type I error rate.
abstract: It is shown that the procedure of applying the Wilcoxon test after Levene's transformation can have an inflated Type I error rate when distributions are skewed. Thus, when the data may come from an asymmetric distribution, the Wilcoxon test should not be applied as a test for homogeneity of variances after Levene's transformation.
authors.affiliation: Department of Mathematics and Statistics, University of Otago. markus.neuhaeuser@medizin.uni-essen.de
authors.forename: Markus
authors.initials: M
authors.lastname: Neuhäuser
mesh_terms: D006801:Humans; D011589:Psychology, Experimental / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012107:Research Design; D016008:Statistical Distributions; D018709:Statistics, Nonparametric