[Linear factor analytic models for reliability analysis of composite variables].
BACKGROUND
Confirmatory factor analysis allows testing whether a composite variable may be considered as a reliable measure of a psychological attribute which is defined within a population.


METHODS
Models for parallel, tau equivalent and congeneric measurements are presented along with their reliability coefficients.


RESULTS
When the variables are not tau equivalent, the averaged inter-item correlation should be preferred to coefficient alpha, which is not an estimator of the reliability of the corresponding data. As a rule, interpretation of a coefficient as a reliability coefficient requires that the corresponding structural model of the composite be known. Beyond unidimensionality, simultaneous analysis of several congeneric variables through the use of cross-sectional or longitudinal hierarchical models entails fragmenting the theoretical variables.


CONCLUSIONS
Interpreting a composite variable whose theoretical structure is corroborated by a hierarchical model may raise some difficulties because of its multidimensionality. Reliability formulae which account for this fragmentation are detailed.
Vautier
S
S
Maison de la Recherche, CERPP, B10, Université de Toulouse-Le Mirail, 5, allées Antonio-Machado, 31058 Toulouse Cedex 9. vautier@univ-tlse2.fr
Gaudron
J-P
JP
Jmel
S
S
D005163:Factor Analysis, Statistical; D015233:Models, Statistical; D015203:Reproducibility of Results