Nonparametric statistical tests on data with negative and positive values

Question

[SB]

Dear Biostars Community,

I have some single-sample gene set enrichment scores acquired from gene expression data and would like to perform nonparametric statistical tests such as the Mann-Whitney two-sample test and the Kruskal-Wallis (one-way ANOVA alternative) test. However, since this data contains negative values, will these tests still perform properly?

Thanks,

SB

Answer 1

[Jean-Karim Heriche]

The Mann-Whitney (aka Wilcoxon Rank Sum Test) and Kruskal-Wallis tests only require that you can rank the values and that the samples are independent.