Use a Kruskal-Wallis test to determine whether the medians of two or more groups differ.

This test is an alternative to the one-way ANOVA for cases where the sample data taken at each input level are not reasonably normal. Also, the Mood's median test may be more appropriate than the Kruskal-Wallis median test when outliers are present.

For example, a health administrator wants to compare the number of unoccupied beds in three hospitals. To determine whether the median number of unoccupied beds differs, the administrator uses the Kruskal-Wallis test. To see an example, go to Minitab Help: Example of Kuskal-Wallis Test.

To add output from a Kruskal-Wallis test, go to Add and complete a form.

Data considerations

Your data must have one categorical factor (X) and one continuous response (Y). Data for all the groups must have similarly shaped distributions. For details, go to Minitab Help: Data considerations for Kruskal-Wallis Test.