A Note on Approximating Correlations from Odds Ratios

Abstract
An approximate relationship between the odds ratio and the tetrachoric correlation for 2×2 contingency tables is presented. The approximation is simple in form and demonstrates a close linkage between these two important measures of association. This relationship can be used to reconcile (at least in part) the two ostensibly different ways to study association or partial association. The approximation is related to Yule's Q and can also be motivated by recent results on association models. The approximation is used to relate the parameters of the common factor model and the 2-class latent structure model applied to dichotomous items.