----- = Non-parametric tests = ----- === Background === Building site In contast to parametric tests, '''nonparametric tests''' do not assume a particular form of underlying probability distribution. Well-known tests are the Wilcoxon signed rank test, Whitney-Mann-Wilcoxon (WMW) test, Kruskal-Wallis (KW) test, and Friedman's test. [[#top|back]]