Categorical
Pearson's χ² test
Tests association between two categorical variables.
Variables
- Row variableNominal · Ordinal — 1
- Column variableNominal · Ordinal — 1
Options
- Chi-square methodN−1 chi-square · Pearson chi-square · Likelihood ratio (G²)
- Fisher’s exact test
What it reports
2×2 and r×c tables; φ or Cramér's V; expected counts shown.
scipy · formula · Open the accuracy report
When does this apply?
For testing the association between two categorical (nominal or ordinal) variables; they are cross-tabulated into cells, and the expected frequency is shown for every cell. The output is χ², the degrees of freedom, p, and φ or Cramér’s V with a confidence interval; for a 2×2 table, proportions, risk measures and NNT are computed as well. Fisher’s exact test is offered as a separate option and is never switched on automatically.