Kruskal-Wallis test

Tests whether two or more independent samples come from identical populations. For example, you may want to know whether the median bacterial counts in milk are the same from shipment to shipment.

The Kruskal-Wallis test is a nonparametric alternative to a one-way ANOVA. The test does not require the data to be normal, but instead uses the rank of the data values rather than the actual data values for the analysis.