Published online by Cambridge University Press: 01 January 2025
The “longitudinal factor analysis” model, which uniquely resolves factors from two occasions of data representing the same persons measured on the same test battery, is shown to be derivable by application of canonical correlation procedures to factor scores. Interpreted in this light, it is suggested that, in attaining its objective, “longitudinal factor analysis” maximizes temporal stability of factor scores—an emphasis which may be warranted for some types of change but not for others.
Preparation of this manuscript was supported in part by U. S. Office of Education Grant OEG-O-9-580289-4415(010). Grateful acknowledgement is made to an anonymous consulting editor for constructive suggestions.