Reliability of Scales With Second-Order Structure: Evaluation of Coefficient Alpha's Population Slippage Using Latent Variable Modeling.

A readily applicable procedure is discussed that allows evaluation of the discrepancy between the popular coefficient alpha and the reliability coefficient of a scale with second-order factorial structure that is frequently of relevance in empirical educational and psychological research. The approach is developed within the framework of the widely used latent variable modeling methodology and permits point and interval estimation of the slippage of alpha from scale reliability in a population under investigation. The method is useful when examining the consistency of complex structure measuring instruments assessing higher order latent constructs and, under its assumptions, represents a generally recommendable alternative to coefficient alpha. The outlined procedure is illustrated using data from an authoritarianism study.