Nonparametric
Friedman test
Compares three or more repeated measurements by ranks.
Variables
- Repeated measuresContinuous · Ordinal — at least 3
Options
- Post-hoc comparisons
- AdjustmentHolm · Bonferroni · None
What it reports
A nonparametric test for repeated measures; χ², df, p and Kendall W.
scipy+formula · Open the accuracy report
When does this apply?
The same design as the repeated-measures ANOVA — one group’s measurements in at least three separate columns, one row per observation — but the comparison is by ranks within each row, so the measurements may also be ordinal. Two occasions are not accepted: the Wilcoxon signed-rank test covers that case. The output is χ², the degrees of freedom, p, and Kendall’s W as the effect size; pairwise differences are reported under the selected adjustment.