Exploratory factor analysis of the Wechsler Abbreviated Scale of Intelligence (WASI) in adult standardization and clinical samples.

Exploratory factor analyses were conducted separately on the Wechsler Abbreviated Scale of Intelligence (WASI; The Psychological Corporation, 1999) adult standardization sample (n = 1,145) and a diagnostically heterogeneous adult clinical sample (n = 201). In the latter group, means for age, education, and WASI Full Scale IQ were 59.25 years (SD = 17.52), 12.39 years (SD = 2.88), and 89.91 (SD = 16.00). For each sample, the four WASI subtests were subjected to a principal-axis factor analysis followed by varimax and promax rotations. Two factors were specified to be retained. Verbal Comprehension and Perceptual Organization factors were identified in both analyses. Coefficients of congruence were 0.98 for Factor I and 0.99 for Factor II, suggesting factorial equivalence across the standardization and clinical samples.