Omega

Omega is a standalone Windows program to compute omega and omega hierarchical, measures of measurement precision or reliability, using standardized loadings from a bifactor confirmatory factor analysis. A prerequisite to using Omega is a good fitting, completely orthogonal bifactor model. Omega defines reliability in terms of the variance accounted for by all (i.e., general and group) constructs that underlie a scale score whereas omega hierarchical defines reliability in terms of the variance accounted for by a specific target construct (general or group) alone.