title: Structural and incremental validity of the Wechsler Adult Intelligence Scale-Fourth Edition with a clinical sample.
abstract: Structural and incremental validity of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV; Wechsler, 2008a) was examined with a sample of 300 individuals referred for evaluation at a university-based clinic. Confirmatory factor analysis indicated that the WAIS-IV structure was best represented by 4 first-order factors as well as a general intelligence factor in a direct hierarchical model. The general intelligence factor accounted for the most common and total variance among the subtests. Incremental validity analyses indicated that the Full Scale IQ (FSIQ) generally accounted for medium to large portions of academic achievement variance. For all measures of academic achievement, the first-order factors combined accounted for significant achievement variance beyond that accounted for by the FSIQ, but individual factor index scores contributed trivial amounts of achievement variance. Implications for interpreting WAIS-IV results are discussed.
authors.affiliation: Regents' Center for Learning Disorders.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Nelson
authors.affiliation: Department of Psychology, Eastern Illinois University.
authors.forename: Gary L
authors.initials: GL
authors.lastname: Canivez
authors.affiliation: Department of Educational Psychology, Baylor University.
authors.forename: Marley W
authors.identifier: 0000-0001-6352-7174
authors.initials: MW
authors.lastname: Watkins
mesh_terms: D000293:Adolescent; D000328:Adult; D004522:Educational Status; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis*; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation; D015203:Reproducibility of Results; D014888:Wechsler Scales / Q000592:standards*; D055815:Young Adult