Contingency coefficient
= Contingency coefficient
{title2=$C=\sqrt{X^2/(X^2+n)}$}
The <contingency coefficient> transforms the <Pearson chi-squared statistic> as $C=\sqrt{X^2/(X^2+n)}$. It is an unsigned measure of <statistical association>, not a <p-value> or a direction of an ordinal relationship. Writing $\phi^2=X^2/n$ gives $C=\phi/\sqrt{1+\phi^2}$. Unlike <Cramér's V>, its attainable maximum depends on table dimensions, so comparisons between differently sized tables need care.