Kruskal-Wallis H (3 grupos)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
K-W
About this calculator
The Kruskal-Wallis H calculator is a useful tool for statisticians and researchers who want to evaluate the equality of means of three or more groups of data. It is an extension of the Kruskal-Wallis method, which is an alternative to the t-test when the data do not follow a normal distribution.
The underlying formula of the calculator is as follows: H = 12/N(N+1)·Σ(Rⱼ²/nⱼ) − 3(N+1), where H is the test value, N is the total number of observations, Rⱼ is the value of each observation after ordering and nⱼ is the size of each group of observation.
It is important to use this calculator when you want to compare the mean of three or more groups of data, especially when the data do not follow a normal distribution. Additionally, it is essential to consider precautions such as the correct choice of groups and the verification of the distribution of the data before performing the test.
Frequently asked questions
What is the difference between Kruskal-Wallis and t-test?
The main difference between Kruskal-Wallis and t-test is that t-test assumes that the data are normally distributed, while Kruskal-Wallis is an appropriate alternative when the data do not follow a normal distribution.
When to use Kruskal-Wallis?
Use Kruskal-Wallis when you want to compare the mean of three or more groups of data, especially when the data do not follow a normal distribution.
How to choose the groups for the test?
It is essential to choose the groups correctly, considering the characteristics and properties of the data. Additionally, it is crucial to verify the distribution of the data before performing the test.
What is the test value (H)?
The test value (H) is a measure of how the means of the groups differ. Higher values of H indicate greater difference between the means.