Kruskal Wallis Test Using SPSS A Kruskal Wallis test is a rank-based nonparametric test to find out if there is a statistically significant difference between the medians of three or more independent groups or not. At SPSS tutor we perform a Kruskal-Wallis H test assuming that your distributions are not the same shape and you have to interpret mean ranks rather than medians. For more info visit our website: https://spss-tutor.com/kruskal-wallis-test.php