PROBLEM
Valid comparison of scores from a test given to different ethnic or cultural groups rests on the assumption that the test measures the same abilities for the various groups. Unfortunately, this assumption is rarely put to an empirical test. More typically, an investigator who finds differences in the mean test scores of two or more groups questions the make-up of the scale because of these differences. However, mean differences in test scores do not indicate per se that the measurement is on different scales; rather, a technique such as factor analysis is necessary to compare a test's structure across groups.
This study compared the structure of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) for groups of black children and white children. Previous studies", 4 * 9 , have shown that the WPPSI is a 2-factor test for all age groups in the 4-t o 6-Myear range and that the structure follows closely the makeup of the Verbal and Performance Scales. The similarity of the factor structure of the blacks to that of the whites-as well as its similarity to Wechsler's predetermined scale structure-bears upon the question of the appropriateness or "fairness" of WPPSI for black children. The question of mean differences in the WPPSI IQs of white and black children has been discussed el~ewhere'~).
METHOD
Subjects. The WPPSI standardization sample (N = l200), which was divided into three age groups and factor analyzed in the investigators' pervious study(4) of WPPSI, again provided the data source. This sample includes 200 children (172 whites and 28 nonwhites) at each of six age levels between 4 and 6?4(1Β°9 pp. [13][14][15][16][17][18].
Of the 168 nonwhites included in the total sample, 156 are black and 12 are from other nonwhite groups such as Orientals; the latter 12 children were excluded from the present analyses.
Two groups that spanned the entire 4-to 6%-year range were formed for analysis: blacks (N = 156) and whites (N = 1032). Each sample was stratified in accordance with 1960 census figures on the variables of age, sex, geographic region, father's occupation, and urban-rural residence. For the black group, strat-*The authors are grateful to Ramriel Daramola and Robert DiCuio for their assistance in conducting the factor analyses.