Factor Structure of the Italian Version of the Wais—R Compared with the American Standardization

Abstract

Factor analysis for responses to the WAIS–R by 1,630 adults of the Italian standardization sample produced two factor solutions in different age groups, and showed high factorial similarity when compared with the same American solution. An estimate of g factor and variance components showed some difference with American data: a lower proportion of g and common variance, and a greater specificity characterized the Italian version with an almost identical error variance. For both the estimate of g and variance components some change across age groups was observed with g and common variance increasing and specific variance decreasing from youngest to oldest groups.