METHODS FOR ESTIMATING INDIVIDUAL-LEVEL AND GROUP-LEVEL CORRELATIONS

Kenny and La Voie (1985) have emphasized the importance of distinguishing between individual- and group-level correlations in small-group research. Unfortunately, there is confusion in the social psychological literature about how to best estimate correlations at these 2 levels. The present article describes and compares 5 different estimators of correlations at the individual and group level. It is recommended that either the modified-method-of-moments estimator or one of two maximum-likelihood estimators be used in preference to the method-of-moments estimator or Kenny and La Voie's estimator. The 3 recommended estimators often will give similar results, so the choice among them often won't make much difference. Similar considerations apply when estimating regression coefficients and parameters in structural equation models.