Comparison Of Oblique And Orthogonal Simple Structure Solutions For Personality And Interest Factors

The study was directed to the need to structure in a few variables the domain measured by personality and interest measures commonly employed in educational counseling: Strong, Kuder, EPPS and the Study of Values. Despite initial uncertainty regarding number of factors to be employed, effects of ipsative scores and of mixing test formats, both an oblique and orthogonal rotation yielded nearly identical results. Of the twenty factors identified by both the biquartimin and varimax solutions, Seven linked vocational interest clusters with personality. Two of the remaining factors had only interest loadings, while of the eleven personality factors, only four were scale specific. Definition of the 16 common factors required that extraction proceed beyond the unit latent root criterion. The results offer evidence that over- extracting factors does not confuse the results of rotation. Further, psycho- metric differences between tests had essentially no effect on the factors found. Of three oblimin rotations attempted, only the biquartimin was successful, yielding results essentially like those of the varimax solution. Because of the vast difference in computation time for these two solutions (computer time 20 times greater for biquartimin), however, the orthogonal varimax remains the method of choice.