Factor analysis studies
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Decker, S. L. (2002). Confirmatory models of sensory/motor and cognitive constructs. Dissertation Abstracts International: Section B: The Sciences & Engineering, 63((2-B)), 1083. (click here and here for two separate files)

Abstract: This study examined the relationship between neuropsychological constructs of sensory- motor functioning and cognitive ability constructs in the Cattell-Horn-Carroll (CHC) (Carroll, 1993) theory. Two studies were conducted. For the first study, the Dean- Woodcock Sensory Motor Battery (SMB) (Dean &Woodcock, 1999) was administered to 800 individuals. A factor analysis and a confirmatory factor analysis were used to investigate and develop a factor structure of the SMB. Results from this study suggest sensory and motor tests significantly share common variance and a hierarchical, multifactorial model that included a higher-order factor of both sensory and motor tests best fit the data. The second study examined the SMB model, developed in the first study, in relation to the CHC (Cattell- Horn-Carroll) model of cognitive abilities, as measured by the Woodcock- Johnson Revised Tests of Cognitive Abilities (WJ-R) (McGrew, Werder, &Woodcock, 1991). For this study, the SMB and the WJ-R was administered to 411 individuals. A confirmatory model was tested that included the higher-order factor of the SMB as a broad ability within the CHC model. Results from this analysis suggest the higher order factor of the SMB does have a significant relationship with overall measures of cognitive ability of a similar level to other broad abilities in the CHC model, and significantly improves the fit of CHC model. These results support Roberts, Pallier, and Goff's (1999) argument for the inclusion of an additional broad ability in the CHC taxonomy that represents sensory and motor functioning. Additionally, this study provides empirical support for the utility of including neuropsychological tests of sensory and motor functioning in a comprehensive assessment of cognitive abilities (Dean & Woodcock, 1999). The implications for neuropsychological and psychometric assessment are discussed.
 
Edwards, O & Oakland, T. (2006) Factorial Invariance of Woodcock-Johnson III Scores for African Americans and Caucasian Americans.  Journal of Psychoeducational Assessment, 24 (4), 358- 366. (click here)
Abstract.  Bias in testing has been of interest to psychologists and other test users since the origin of testing. New or revised tests often are subject to analyses that help examine the degree of bias in reference to group membership based on gender, language use, and race/ethnicity. The pervasive use of intelligence test data when making critical and, at times, life-changing decisions warrants the need by test developers and test users to examine possible test bias on new and recently revised intelligence tests. This study investigates factorial invariance and criterionrelated validity of the Woodcock-Johnson III for African American and Caucasian American students. Data from this study suggest that although their mean scores differ, Woodcock- Johnson III scores have comparable meaning for both groups.
 
Frazier, T. & Youngstrom, E. (2007).  Historical increase in the number of factors measured by commercial tests of cognitive ability: Are we overfactoring?  Intelligence, 35, 169–182.  (click to view)
 
Abstract:  A historical increase in the number of factors purportedly measured by commercial tests of cognitive ability may result from four distinct pressures including: increasingly complex models of intelligence, test publishers' desires to provide clinically useful assessment instruments with greater interpretive value, test publishers' desires to includeminor factors thatmay be of interest to researchers (but are not clinically useful), and liberal statistical criteria for determining the factor structure of tests. The present study examined the number of factors measured by several historically relevant and currently employed commercial tests of cognitive abilities using statistical criteria derived from principal components analyses, and exploratory and confirmatory factor analyses. Two infrequently used statistical criteria, that have been shown to accurately recover the number of factors in a data set, Horn's parallel analysis (HPA) and Minimum Average Partial (MAP) analysis, served as gold-standard criteria. As expected, there were significant increases over time in the number of factors purportedly measured by cognitive ability tests (r=.56, p=.030). Results also indicated significant recent increases in the overfactoring of cognitive ability tests. Developers of future cognitive assessment batteries may wish to increase the lengths of the batteries in order to more adequately measure additional factors. Alternatively, clinicians interested in briefer assessment strategies may benefit from short batteries that reliably assess general intellectual ability.
Keith, T. Z., Kranzler, J. H., & Flanagan, D. P. (2001). What does the cognitive assessment system (CAS) measure? Joint confirmatory factor analysis of the CAS and the Woodcock- Johnson tests of cognitive ability (3rd edition).School Psychology Review, 30(1), 89-119.(click to view)
Abstract. Results of recent research by Kranzler and Keith (1999) raised important questions concerning the construct validity of the Cognitive Assessment System (CAS; Naglieri &Das, 1997), a new test of intelligence based on the planning, attention, simultaneous, and sequential (PASS) processes theory of human cognition. Their results indicated that the CAS lacks structural fidelity, leading them to hypothesize that the CAS Scales are better understood from the perspective of Cattell-Horn- Carroll (CHC) theory as measures of psychometric g, processing speed, short-term memory span, and fluid intelligence/broad visualization. To further examine the constructs measured by the CAS, this study reports the results of the first joint confirmatory factor analysis (CFA) of the CAS and a test of intelligence designed to measure the broad cognitive abilities of CHC theory-- the Woodcock-Johnson Tests of Cognitive Abilities-3rd Edition (WJ III; Woodcock, McGrew, & Mather, 2001). In this study, 155 general education students between 8 and 11 years of age (M = 9.81) were administered the CAS and the WJ III. A series of joint CFA models was examined from both the PASS and the CHC theoretical perspectives to determine the nature of the constructs measured by the CAS. Results of these analyses do not support the construct validity of the CAS as a measure of the PASS processes. These results, therefore, question the utility of the CAS in practical settings for differential diagnosis and intervention planning. Moreover, results of this study and other independent investigations of the factor structure of preliminary batteries of PASS tasks and the CAS challenge the viability of the PASS model as a theory of individual differences in intelligence.
 
Kranzler, J. H., Keith, T. Z., & Flanagan, D. P. (2000). Independent examination of the factor structure of the cognitive assessment system (CAS): Further evidence challenging the construct validity of the CAS. Journal of Psychoeducational Assessment, 18(2), 143- 159.  (click to view)
Abstract.  This study is the first to examine independently the factor structure of the Cognitive Assessment System (GAS; Naglieri & Das, 1997) with a primary dataset not collected by its authors. Participants were 155 students (59 boys, 96 girls), ages 8 to 11 (M = 9.81 years, SD = 0.88), in Grades 3 to 6. Confirmatory factor analysis (CFA) was used to compare the fit provided by the planning, attention, and simultaneous- successive (PASS) model, the theoretical model underlying the CAS, with alternative models of cognitive ability suggested by previous research. Results of this study indicated that the PASS model did not provide a better fit to the data than did alternative hierarchical and nonhierarchical models. Not only were the Planning and Attention factors of the PASS model virtually indistinguishable (r = .88), but they demonstrated inadequate specificity for meaningful interpretation. The model reflecting the actual hierarchical structure of the CAS was found to fit the data no better than alternative models based on different theoretical orientations. Of the hierarchical models examined in this study, the best fitting was a hierarchical (PA)SS model with one second-order general factor, psychometric g, and three first- order factors reflecting Fluid Intelligence/Visual Processing (Simultaneous), Memory Span (Successive), and Processing Speed (Planning/Attention). In sum, results of this study support Kranzler and Keith's (1999) conclusion that the CAS lacks structural fidelity, which means that the CAS does not measure what its authors intended it to measure. Results of this study, therefore, provide further evidence challenging the construct validity of the CAS.
 
Lamanati, A. E. (2004). Comparing rates of improvement on the Woodcock Johnson-Revised among emotionally disturbed children.Dissertation Abstracts International: Section B: The Sciences & Engineering, 64(10-B), 5222.

Abstract:  Archival data was obtained for 100 students enrolled at Alicante School. Participants were randomly drawn. Each was classified as emotionally disturbed (ED). It was hypothesized that low scoring ED students would show a significant rate of acquisition (improvement) on achievement scores as measured by the Woodcock Johnson- Revised (WJR), following one year exposure to the Alicante School Program. Results suggest there were no significant trends among demographics. There was a decline on the Applied Problems subscale, whereas the remaining subscale stayed constant across time. An exploratory analysis revealed ethnicity had an impact on test scores.
 
League, S. E. (2001). A joint factor analysis with the Woodcock-Johnson Tests of Cognitive Abilities - Third Edition and the Wechsler Preschool and Primary Scales of Intelligence - Revised. Dissertation Abstracts International Section A: Humanities & Social Sciences, 61((7- A)), 2594.

Abstract: Educational services for preschool children with disabilities are mandated by the individuals with Disabilities Act (IDEA; United States Statutes At Large, June 4, 1997). Norm- referenced measures of cognitive ability are used in determining a child's eligibility for these services. Tests which are used should be sensitive to the nature of children's cognitive abilities, and thus should assess the variety of abilities and skills preschool children use when interpreting and processing information. In an effort to determine how different tests assess the nature of children's cognitive abilities, this study utilized two commonly used, norm-referenced measures of cognitive abilities among preschool children. Tests from the Woodcock- Johnson Tests of Cognitive Abilities - Third Edition (Woodcock, McGrew, and Mather, 2001) and the Wechsler Preschool and Primary Scales of Intelligence Revised (WPPSI-R; Wechsler, 1989) were administered to a sample of 164 children, ages three years and zero months to five years and eleven months. Confirmatory factor analyses were conducted to determine the underlying factor structure and constructs measured by each of these tests. Additionally, joint confirmatory analyses were conducted to determine the model that best fits the combined data set. Four distinct models were compared in these analyses: a singles- factor structure representing general intelligence, a two-factor structure representing verbal and nonverbal functioning, a three- factor structure representing verbal, nonverbal, and freedom from distractibility/attention, and a hierarchical model including the general intelligence factor and seven specific CHC factors. A two- factor structure representing verbal and nonverbal abilities was supported for the WPPSI-R. A three or four- factor structure, including comprehension-knowledge (Gc), visual-spatial thinking (Gv), processing speed (Gs) and short- term-memory (Gsm), was supported for the WJ III data set and a two-factor structure representing verbal and nonverbal abilities was supported for the combined data set. The results of this study provided validity information for two measures of cognitive abilities: the Wechsler Preschool and Primary Scale of Intelligence - Revised (WPPSI- R; Wechsler, 1989) and the Woodcock- Johnson Tests of Cognitive Abilities - Third Edition (WJ III; Woodcock, McGrew, & Mather, 2001). Test instruments and assessment techniques should provide measures of diverse abilities. Hypotheses regarding the skills measured by different test and subtests, on different batteries, given a Gf-Gc or CHC theoretical orientation, are provided in McGrew and Flanagan (1998). School psychologists can use this resource in order to better design test batteries to measure a variety of cognitive abilities across age levels. Future research is needed in order better to clarify the underlying structure of cognitive abilities among preschool age children.
 
Hiramoto, J. F. (2005). "Reaction time speed" as a factor in the Cattell-Horn-Carroll theory of cognitive abilities: Evidence for or against (Raymond Cattell, John Horn, John Carroll).Dissertation Abstracts International Section A: Humanities and Social Sciences., 66(2-A).
 
 
Phelps, L., McGrew, K. S., Knopik, S. N., & Ford, L. (2005). The general (g), broad, and narrow CHC stratum characteristics of the WJ III and WISC-III tests:  A confirmatory cross- battery investigation. School Psychology Quarterly, 20(1), 66-88. (click to view)
Abstract: One hundred, forty-eight randomly selected children (grades three-five) were administered the WISC-III, WJ III Tests of Cognitive Abilities, WJ III Tests of Achievement, and seven research tests selected from the WJ III Diagnostic Supplement. The validity of the existing WISC-III and WJ III broad Cattell-Horn- Carroll (CHC) test classifications was investigated via the application of CHC- organized, broad-   factor, cross-battery confirmatory factor analyses (CFA). Likewise, the validity of the WISC-III and WJ III narrow CHC ability classifications was investigated via the evaluation of a three-stratum hierarchical (narrow+broad+g)CHC CFA cross- battery model. The Tucker- Lewis Index, the Comparison Fit Index, and the Root Mean Square Error of Approximation evaluated the fit for the resulting models. All statistical values indicated good to excellent fit. 
 
 
Sanders, S., McIntosh, D. & Dunham, M.  2004). A joint confirmatory factor analysis of the Differential Ability Scales and the Woodcock-Johnson Tests of of Cognitive Abilities--Third Edition.   Psychology in the Schools, 44(2), 119-138. (click to view).
 
This study examined the underlying constructs measured by the Differential Ability Scales (DAS; C.D. Elliott, 1990a) as they relate to the Cattell-Horn-Carroll (CHC) Theory (K.S. McGrew, 1997) of cognitive abilities. The DAS and Woodcock-Johnson Tests of Cognitive Abilities (WJIII COG; R.W. Woodcock, K.S. McGrew, & N. Mather, 2001) were administered to 131 children in grades 3 through 5 who took part in a concurrent validity study included in the Woodcock- Johnson Tests of Cognitive Abilities, Third Edition, technical manual (K.S. McGrew & R.W. Woodcock, 2001). Confirmatory factor analyses using maximum likelihood estimation were conducted with the AMOS 5.0 (J.L. Arbuckle, 2001) statistical program to evaluate three models of increasing complexity, to compare how well each fit the data set, and to identify the one that best described the underlying constructs measured by the DAS. Results suggested that the synthesized Three-Stratum CHC Model provided the most parsimonious representation among the three models tested.
 
Teague, T. L. (2002). Joint factor-analytic investigation of the Differential Ability Scales and the Woodcock-Johnson Tests of Cognitive Abilities-Third Edition with preschool-age children.Dissertation Abstracts International Section A: Humanities & Social Sciences, 62((7-A)), 2338.

Abstract: Assessment of preschool-age children suspected of developmental delays is necessary to determine their eligibility for special services. However, the assessment of young children with standardized measures is often considered a controversial practice. The use of standardized tests with preschool age children has been critiqued, including criticisms regarding the lack of adequate technical characteristics and that relatively little is known about the nature of preschool cognitive functioning as is measured by standardized tests. Given these and other critiques, additional research with preschool assessment tools is needed to better understand the technical characteristics of the tests as well as to better understand the nature cognitive abilities in preschool age children. The purpose of this study was to examine the utility of two tests used with preschool age children, the Differential Ability Scales - Preschool Version (Elliott, 1990a) and the Woodcock- Johnson Tests of Cognitive Abilities - Third Edition (Woodcock, McGrew, & Mather, in press). Support was found for the DAS as a measure of two abilities (Verbal and Nonverbal) as well as multiple Gf-Gc abilities, with both findings consistent with previous research. For the WJ-III, a seven factor Gf-Gc model was not supported. Joint analyses examining the DAS and WJ-III with the seven Gf-Gc abilities failed to support this multiple ability theory as well. Independent and joint post-hoc analyses of the two tests exploring additional models failed to receive support. Implications of these findings and future avenues for research investigating multiple cognitive abilities in preschool children are discussed.
 
Tusing, M. B., & Ford, L. (2004). Examining preschool cognitive abilities using a CHC framework.International Journal of Testing, 4(2), 91-114. (click to view)
Abstract: Although there has been a substantial growth in the number of published studies examining tests of cognitive abilities and using contemporary theories of cognitive abilities, to date none have done so with preschool cognitive tests. In this study the relation between cognitive ability measures for young children and Cattell–Horn–Carroll (CHC) theory is examined. Tests and subtests from the Differential Ability Scales: Upper Preschool Level and the Woodcock–Johnson Tests of Cognitive Ability–Revised with a sample of 158 children between 4 and 5 years of age were used in a series of joint factor analyses. Although a series of models were explored, the model representative of the CHC theory of cognitive abilities was best supported by the data. This provides evidence for a greater differentiation of young children’s cognitive abilities than are typically interpreted. Results are discussed with regard to understanding the link between contemporary theories of intelligence and young children’s cognitive abilities, as well as implications for intellectual assessment practices with young children. 
 
Williams, T. H. (2005).  A joint-confirmatory factor analysis using the Woodcock-Johnson Tests of Cognitive Ability - Third Edition and the Stanford-Binet Intelligence Scales: Fifth Edition with high- achieving children. Dissertation Abstracts International:  Section B: The Sciences and Engineering.,  66(5- B).