Congeneric modeling of reliability using censored variables

Abstract

This paper explores the use of Jöreskog’s (1970) congeneric modeling approach to reliability using censored quantitative variables, and discusses the compound problem of non-normality and attenuation that occurs when estimating censored continuous variables. Two monte carlo studies were conducted. The first study demonstrated the inappropriateness of using normal theory generalized least-squares (NTGLS) for estimating reliability on censored variables. The second study compared three different estimation procedures- NTGLS, asymptotically distribution free (ADF) estimators, and latent TOBIT estimators-as to their efficiency in estimating individual and composite reliability on censored variables. Results from the studies indicate that problems of non-normality and attenuation must be addressed before accurate reliability estimates may be obtained. Index terms: censored variables, congeneric model, covariance modeling, monte carlo study, reliability, TOBIT correlations.