Friedman test
Hypothesis tests · Method and input reference
Each line is a group. Repeated measures and Friedman require the same subjects in matching positions. Dunnett uses the first line as control. Parametric ANOVA assumes normal independent errors; repeated ANOVA assumes sphericity. Synthetic example: 48 people at baseline and three follow-ups; each row is a visit and each column is the same person.
Open calculator · Compare methods in the decision matrix
When to consider it
- Compare ranks across three or more repeated conditions.
Assumptions and scope
- Complete matched blocks; subjects independent of other subjects.
- The chi-square approximation can be poor in small samples; follow-up paired tests need multiplicity adjustment.
Required inputs
- Groups (one group per line) — Numeric observations; preserve the row and column structure described above.
Review missing values and data coding before running. Sample inputs are synthetic teaching examples.
Implementation
Lifescio validates inputs and formats results; listed functions are the principal calculation routines, not an exhaustive transitive dependency list.
- scipy 1.15.3: scipy.stats.friedmanchisquare
These are pinned library versions; saved results record the versions actually used at runtime.