public class KruskalWallisTestextends StatisticalTestThe Kruskal-Wallis test. This test is the natural extension of the two-sample Wilcoxon test for location to the case of k independent samples. Assuming the location model, the null hypothesis is that the k medians of the populations are equal, whereas the alternative is that at least two location parameter differ. Ties are broken by the midrank method (e.g. a tie in ranks 6 and 7 is assumed as a 6.5 rank for both values). A multiple-comparisons procedure (Bonferroni-Dunn), applied at 0.10 and 0.05 levels of significance is also provided.