Reliability of scales with general structure: Point and interval estimation using a structural equation modeling approach

A method for obtaining point and interval estimates of reliability for composites of measures with a general structure is discussed. The approach is based on fitting a correspondingly constrained structural equation model and generalizes earlier covariance structure analysis methods for scale reliability estimation with congeneric tests. The procedure can be used with weighted or unweighted composites, in which the weights need not be known in advance but may be estimated simultaneously. The approach allows one also to obtain an approximate standard error and confidence interval for scale reliability using the bootstrap methodology.