Factor Analysis of the WAIS-R Using the Factor Replication Procedure, FACTOREP

The factor structure of the WAIS-R has been the subject of much debate and recently researchers have examined multiple independent samples and compared the resulting factor structures using the coefficient of congruence. On the basis of this, one recent study concluded that the WAIS-R had three clear factors. In the present study this conclusion was questioned and it was claimed that the previous result was an artifact caused by the large general factor found in the WAIS-R. The present study aimed to clarify the situation by using identical data but the alternative factor comparison technique, FACTOREP, which was able to reduce the influence of both error variance and the general factor. On the basis of this comparison it was demonstrated that the WAIS-R has two strong factors but that there is little evidence for the existence of a third factor.