Confirmatory Factor Analyses (CFA) of the Wechsler Adult Intelligence Scale—III (WAIS-III) lend partial support to the four-factor model proposed in the test manual. However, the Arithmetic subtest has been especially difficult to allocate to one factor. Using the new Norwegian WAIS-III version, we tested factor models differing in the number of factors and in the placement of the Arithmetic subtest in a mixed clinical sample (n = 272). Only the four-factor solutions had adequate goodness-of-fit values. Allowing Arithmetic to load on both the Verbal Comprehension and Working Memory factors provided a more parsimonious solution compared to considering the subtest only as a measure of Working Memory. Effects of education were particularly high for both the Verbal Comprehension tests and Arithmetic.
Arnau, R., & Thompson, B. (2000). Second-order confirmatory factor analysis of the WAIS-III. Assessment, 7, 237-246.
2.
Baddeley, A.D., Bressi, S., Della Sala, S., Logie, R., & Spinnler, H. (1991). The decline of working memory in Alzheimer's disease . Brain, 114, 2521-2542.
3.
Bowden, S.C., Weiss, L.G., Holdnack, J.A., & Lloyd, D. (2006). Age-related invariance of abilities measured with the Wechsler Adult Intelligence Scale-III. Psychological Assessment , 18, 334-339.
4.
Burton, D.B., Ryan, J.J., Axelrod, B.N., & Schellenberger, T. (2002). A confirmatory factor analysis of the WAIS-III in a clinical sample with cross validation in the standardization sample. Archives of clinical Neuropsychology , 17, 371-387.
5.
Delis, D.C., Jacobson, M., Bondi, M.W., Hamilton, J.M., & Salmon, D.P. (2003). The myth of testing construct validity using factor analysis or correlations with normal or mixed clinical populations: Lessons from memory assessment. Journal of the International Neuropsychological Society, 9, 936-946.
6.
Dickinson, D., Iannone, V.N., & Gold, J.M. (2002). Factor structure of the Wechsler Adult Intelligence Scale-III in Schizophrenia. Assessment, 9, 171-180.
7.
Egeland, J., Rund, B.R., Sundet, K., Landrø, N.I., Asbjørnsen, A., Lund, A., et al. (2003). Attention profile in schizophrenia compared to depression: Differential effects of processing speed, selective attention and vigilance. Acta Psychiatrica Scandinavica, 108, 276-284.
8.
Garcia, L.F., Ruiz, M.A., & Abad, F.J. (2003). Factor structure of the Spanish WAIS-III (Spanish) . Psicothema, 15, 155-160.
9.
Goldman-Rakic, P.S. (1994). Working memory dysfunction in schizophrenia. Journal of Neuropsychiatry and Clinical Neurosciences, 6, 348-357.
10.
Gregoire, J. (2004). Factor structure of the French version of the Wechsler Adult Intelligence Scale-III. Educational and Psychological Measurement, 64, 463-474.
11.
Hartmann, C.A., Wilcutt, E.G., Rhee, S.H., & Pennington, B.F. (2004). The relation between sluggish cognitive tempo and DSM-IV ADHD. Journal of Abnormal Child Psychology, 32, 491-503.
12.
Heaton, R.K., Taylor, M.J., & Manly, J.J. (2003). Demographic effects and the use of demographically corrected norms with the WAIS-III and WMS-III. In D. S. Tulsky et al., (Eds.), Clinical interpretation of the WAIS-III and WMS-III (pp. 181-210). San Diego, CA: Academic Press.
13.
Horn, J.L., & Blankson, N. (2005). Foundations for better understanding of cognitive abilities. In D. P. Flanagan & P. L. Harrison (Eds.), Contemporary intellectual assessment (pp. 41-68). New York: Guildford .
14.
Jöreskog, K., & Sörbom, D. (1993). LISREL 8: Structural equation modeling with the SIMPLIS command language. Lincolnwood, IL: Scientific Software International.
15.
Kaufman, A.S. (1979) Intelligent testing with the Wisc-r. New York: John Wiley.
16.
Kaufman, A.S., Lichtenberger, E.O., & McLean, J.E. (2001). Two and three-factor solutions of the WAIS-III. Assessment, 8, 267-280.
17.
Keith, T.Z. (2005). Using confirmatory factor analysis to aid in understanding the constructs measured by intelligence tests. In D. P. Flanagan & P. L. Harrison (Eds.), Contemporary intellectual assessment (pp. 581-614). New York: Guildford.
18.
Psychological Corporation. (2002). WAIS-III & WMS-III technical manual. San Antonio TX : Author.
19.
Nyman, H., & Nordvik, H. (2003). WAIS_III Manual. Norsk versjon [Norwegian Version] . Stockholm, Sweden: Psykologiförlaget .
20.
Pelletier, P.M., Ahmad, S.A., & Rourke, B.P. (2001). Classification rules for basic phonological processing disabilities and nonverbal learning disabilities: Formulation and external validity. Child Neuropsychology, 7, 84-98.
21.
Ryan, J.J., & Paolo, A.M. (2001). Exploratory factor analysis of the WAIS-III in a mixed patient sample. Archives of Clinical Neuropsychology , 16, 151-156.
22.
Saklofske, D.H., Hildebrand, D.K., & Gorsuch, R.L. (2000). Replication of the factor structure of the Wechsler Adult Intelligence Scale-Third Edition with aCanadian sample. Psychological Assessment, 12, 436-439.
23.
Statistics Norway. (2007). Population's level of education, 1. October 2006. Retrieved August 25, 2008 , from http://www.ssb.no/english/subjects/04/01/utniv_en/
24.
Tipper, C.M., Cairo, T.A., Woodward, T.S., Philips, A.G., Liddle, P.F., & Ngan, E.T. (2005). Processing efficiency of a verbal working memory system is modulated by amphetamine : An fMRI investigation. Psychopharmacology, 180, 634-643.
25.
Tulsky, D.S., Ivnik, R.A., Price, L.R., & Williams, C. (2003). Assessment of cognitive functioning with the WAIS-III and WMS-III. Development of a six factor model. In D. S. Tulsky et al., (Eds), Clinical interpretation of the WAIS-III and WMS-III (pp. 147-179). San Diego, CA: Academic Press.
26.
Tulsky, D.S., & Price, L.R. (2003). The joint WAIS-III and WMS-III factor structure: Development and cross-validation of a six-factor model of cognitive functioning . Psychological Assessment, 15, 149-162.
27.
van der Heijden, P., & Donders, J. (2003). A confirmatory factor analysis of the WAIS-III in patients with traumatic brain injury. Journal of Clinical and Experimental Neuropsychology, 25, 59-65.
28.
Ward, L.C., Ryan, J.J., & Axelrod, B.N. (2000). Confirmatory factor analysis of the WAIS-III standardization data. Psychological Assessment, 12, 341-345.
29.
Wasserman, J.D., & Tulsky, D.S. (2005). A history of intelligence assessment. In D. P. Flanagan & P. L. Harrison (Eds.), Contemporary intellectual assessment (pp. 3-22). New York: Guildford.
30.
Wechsler, D. (1997a). The Wechsler Adult Intelligence Scale (3rd ed.). San Antonio, TX: Psychological Corporation.
31.
Wechsler, D. (1997b). The Wechsler Intelligence Scale for Children-III . San Antonio, TX: Psychological Corporation.
32.
Zhu, J., & Weiss, L. (2005). The Wechsler Scales. I Flanagan & Harrison (Eds.), Contemporary intellectual assessment. Theories, tests and issues (2nd ed., pp. 297-324). New York: Guilford.
