# Cramér's V

Cramér’s V is an effect size measurement for the chi-square test of independence. It measures how strongly two categorical fields are associated.

The effect size is calculated in the following manner:

- Determine which field has the fewest number of categories.
- Subtract 1 from the number of categories in this field.
- Multiply the result by the total number of records.
- Divide the chi-square value by the previous result. The chi-square value is obtained from the chi-square test of independence
- Take the square root.

Effect size (ES) | Interpretation |
---|---|

ES ≤ 0.2 | The result is weak. Although the result is statistically significant, the fields are only weakly associated. |

0.2 < ES ≤ 0.6 | The result is moderate. The fields are moderately associated. |

ES > 0.6 | The result is strong. The fields are strongly associated. |