Missing data are a pervasive problem in many psychological applications in the real world. In this article we study the impact of dropout on the operational characteristics of several approaches that can be easily implemented with commercially available software. These approaches include the covariance pattern model based on an unstructured…

The determinacy of variables in a structural equation model is considered, and it is shown that when the variables in the structural model are all manifest, the error-terms (disturbances) are uniquely determined given the parameters of the data. When the variables are all latent, the error-terms have indeterminate components. (SLD)