Stability of the WISC-R factor structure across sex at two age levels

Factor analyzed intercorrelations of the 12 WISC-R subtests separately for males and females (N = 2,200) at two age levels. Through the method of principal factors, with R2 as initial communality estimates, a three-factor solution was obtained for each of the four groups. The three principal factors were rotated according to the Varimax criteria. Coefficients of congruence were calculated to determine the degree of stability of the three-factor solution across sex at the two age levels. Consistently high coefficients of congruence indicated that the WISC-R factor structure is essentially invariant with regard to sex and age.