Stability of the WAIS-R and WISC-III factor structure using cross-validation of covariance structures.

The stability of the Verbal Comprehension, Perceptual Organization, and Freedom from Distractibility factors of the WAIS-R and WISC-III was tested using cross-validation of covariance structure models, a methodology that employs unrestricted and restricted factor analyses. Stability was indicated if the goodness of fit of restricted models generated from unrestricted factor patterns did not degrade when applied to other age groups. If goodness of fit degraded inconsistently, the factor structure of one or both instruments was unreliable. If goodness of fit changed in some systematic fashion, an argument for true intellectual changes could be made. Results indicated consistency across age groups. Therefore, it was concluded that the three-factor structure is robust and reliable across age groups and instruments.