Abstract
The McCarthy Scales of Children's Abilities (MSCA) were factor analyzed at five age levels: 2½, 3-3½, 4-4½, 5-5½, and 6½-7½-8½. The standardization sample (N = 1032) provided the source of data. Varimax rotated factors akin to four of the six MSCA Scales— General Cognitive, Verbal, Memory, and Motor—appeared at age 2½, and tended to appear at all older age levels. Factors akin to the Perceptual-Performance and Quantitative Scales emerged at ages 3-3½ and 5-5½, respectively. The overall findings were interpreted from a developmental perspective, and the data were shown to offer evidence for the construct validity of the MSCA.