General Association Statistic:
The general association statistic is one of the statistics used in the generalized Cochran-Mantel-Haenszel tests . It is applicable when both the “treatment” and the “response” variables are measured on a nominal scale .
If the treatment and response variables are independent in all strata, the asymptotic distribution of the general association statistic is the chi-square distribution with (R-1)(C-1) degrees of freedom , where R is the number of treatment groups (rows), and C is the number of the “response” values (columns).
The general association statistic tends to take on higher values if the distribution of the “response” depends on the “treatment” in at least one strata.