Friedman Test Calculator

If you want to calculate a Friedman test, you can do it right here in your browser with just a few clicks. Simply select more than two metric variables and click on Nonparametric Test or select more than two ordinal variables.

The Friedman's test calculator tells you whether the dependent groups are significantly different from each other. The results are clearly presented.

If the p-value calculated using the Friedman test is less than the specified significance level (usually 5%), then the null hypothesis is rejected and there is strong evidence that there is a difference between the groups.

When the null hypothesis has been rejected, it is possible to test which groups are different. The Dunn-Bonferroni test (pairwise comparison) is output for this purpose.

What is the Friedman Test?

The Friedman test test is a statistical method designed for analyzing data that's been repeatedly measured. It's often used when the data doesn't meet the requirements for normal distribution and equal variances, making it a suitable alternative to the repeated measures ANOVA.

The hypotheses for the Friedman test are:

• Null Hypothesis (H0):The distributions of the treatments (or groups) are the same across repeated measures. This implies that there is no significant difference in the ranking of the treatments across multiple test attempts.
• Alternative Hypothesis (H1):The distributions of the treatments are different across some (or all) test attempts. This suggests that at least one treatment has a different ranking compared to the others.

If the Friedman test indicates a significant result, it suggests that the rankings of the treatments differ and that the null hypothesis can be rejected. However, to determine which treatments are different from each other, post-hoc pairwise comparisons would be necessary.

Calculate Friedman test

The Friedman test is a non-parametric test and for the calculation not the mean values of the dependent groups are compared, but the rank sums. This has the advantage that the data do not have to be normally distributed.

In contrast to SPSS or Excel, the Friedman test can be calculated directly online with the DATAtab statistical software.

When do you calculate a Friedman test?

A Friedman test is calculated whenever you want to compare more than two dependent groups and the assumptions for calculating an analysis of variance with repeated measures are not met. If you don't have a dependent sample, then just use the Kruskal-Wallis test calculator.