The Cattell-Horn-Carroll (CHC) taxonomy of cognitive abilities married John Horn and Raymond Cattell's Extended Gf-Gc theory with John Carroll's Three-Stratum Theory. While there are some similarities in arrangements or classifications of tasks (observed variables) within similar broad or narrow dimensions, other salient theoretical features and…

Federal law requires that individuals with handicapping conditions be administered assessments in ways that accommodate their disabilities without penalizing them. Validation studies are needed to evaluate the meaning of scores resulting from nonstandard test administrations. The limited number of these studies to date is reviewed. (SLD)