KruskalWallisv

KruskalWallisv is a statistical test used to determine whether there are statistically significant differences between the medians of two or more independent groups. It is a non-parametric method, meaning it does not assume a normal distribution of the data. This test is particularly useful when dealing with ordinal data or when the assumptions of other parametric tests, such as ANOVA, are not met.

The Kruskal-Wallis test is an extension of the Mann-Whitney U test, which is used for comparing two groups. The test statistic for the Kruskal-Wallis test is calculated by ranking all the observations across all groups and then comparing the ranks within each group. The test statistic is then compared to a chi-square distribution to determine the p-value, which indicates the probability that the observed differences are due to chance.

The Kruskal-Wallis test is widely used in various fields, including biology, psychology, and social sciences, where researchers often encounter non-normally distributed data. It is a robust and versatile tool for comparing multiple groups, providing a reliable way to assess differences in medians without making strong assumptions about the underlying data distribution.