Whether the one- or two-factor Wechsler or weighted sum scores (WSS) structural models adequately fit the Wechsler Intelligence Scale for Children III (WISC-III) covariance matrices was studied with samples of 2200 and 1118 children from previous studies. Both the WSS and supplemented models provided better fit than Wechsler's model but still…

Structure of measures of speed was studied by conducting simultaneous confirmatory factor analysis for 1 sample of 149 elderly adults and a sample of 147 young adults using 16 measures of speed. Five first-order factors of speed were found, as hypothesized, and three second-order speed factors were necessary. (SLD)

This study attempts to determine whether the pattern of human abilities varies or remains constant over a range of ability levels. Scores on 12 aptitude and achievement tests for 11,743 subjects, subdivided into four groups according to intelligence and socioeconomic status, were used. A technique, developed by Joreskog, for simultaneously factor…