Analyses of General Educational Development (GED) ratings of U.S. jobs illustrate the estimation of components of variance and covariance, univariate nd multivariate generalizability coefficients, and canonical coefficients. GED scales, ranging from one to six points, measure reasoning, mathematics, and language abilities needed to perform various…

In response to Webb and Shavelson (EJ 241 567), Nussbaum questions the relevance of the universe score variance as a meaning reliability index and whether it is useful to determine the weights which enter into a composite by means of maximum generalizability. (CM)

Answering Nussbaum's (TM 507 069) criticism, the generalizability coefficient for absolute decisions, the use of the error variance formula, composites of maximum generalizability, and covariance components are discussed as yardsticks of measurement precision with arguments for the use of each procedure to interpret data. (CM)