Factor structure of the Wechsler Intelligence Scale for Children-Third Edition among gifted students

Factor analysis was applied to the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) scores of 505 gifted students to evaluate the construct validity of the WISC-III with this population. Multiple criteria were used to determine the number of factors to retain for principal axis extraction. A two-factor solution that roughly mirrored the verbal comprehension and perceptual organization factors of the WISC-III normative sample appeared to be most supportable. Arithmetic, Picture Arrangement, and Coding subtests failed to contribute to this solution. These results are consistent with the hypothesis that subtests that emphasize speed of responding are not valid for gifted children and suggest that an alternative WISC-III composite score, the General Ability Index, may be a better summary of ability for gifted students.