Matching Items (3)
Description
Standardized intelligence tests are some of the most widely used tests by psychologists. Of these, clinicians most frequently use the Wechsler scales of intelligence. The most recent version of this test for children is the Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV); given the multiple test revisions that have occurred with the WISC, it is essential to address evidence regarding the structural validity of the test; specifically, that the internal structure of the test corresponds with the structure of the theoretical construct being measured. The current study is the first to investigate the factor structure of the WISC-IV across time for the same individuals. Factorial invariance of the WISC-IV was investigated using a group of 352 students eligible for psychoeducational evaluations tested, on average, 2.8 years apart. One research question was addressed: Does the structure of the WISC-IV remain invariant for the same individuals across time? Using structural equation modeling methods for a four-factor oblique model of the WISC-IV, this study found invariance at the configural and weak levels and partial invariance at the strong and strict levels. This indicated that the overall factor structure remained the same at test and retest with equal precision of the factor loadings at both time points. Three subtest intercepts (BD, CD, and SI) were not equivalent across test and retest; additionally, four subtest error variances (BD, CD, SI, and SS) were not equivalent across test and retest. These results indicate that the WISC-IV measures the same constructs equally well across time, and differences in an individual's cognitive profile can be safely interpreted as reflecting change in the underlying construct across time rather than variations in the test itself. This allows clinicians to be more confident in interpretation of changes in the overall cognitive profile of individual's across time. However, this study's results did not indicate that an individual's test scores should be compared across time. Overall, it was concluded that there is partial measurement invariance of the WISC-IV across time, with invariance of all factor loadings, invariance of all but three intercepts, and invariance of all but four item error variances.
ContributorsRicherson, Lindsay Patricia (Author) / Watkins, Marley W. (Thesis advisor) / Balles, John R (Thesis advisor) / Lynch, Christa S (Committee member) / Arizona State University (Publisher)
Created2012
Description
The Wechsler Intelligence Scale for Children – ; Fourth Edition (WISC – IV) is one of the most popular intelligence tests used for special education eligibility purposes in the United States. Despite the large prevalence of children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD), the factor structure of the WISC – IV among this population has not been explored. Thus, the factor structure of WISC – IV scores among students with ADHD was investigated via replicatory factor analysis followed by a comparison with the factorial structure of the normative sample using the coefficient of congruence. The four factor model proposed by Wechsler was consistent with the factor structure found in the sample of students with ADHD for all subtests except Picture Concepts and Matrix Reasoning. The Verbal Comprehension and Processing Speed factors appeared to measure the same construct in the study sample as in the normative sample, while the Perceptual Reasoning and Working Memory factors were only fairly similar to the normative sample. It is recommended that clinicians interpret Perceptual Reasoning and Working Memory index scores of students with ADHD cautiously. Limitations of the study, future directions for research, and implications for practitioners are discussed.
ContributorsBoehm, Michelle (Author) / Watkins, Marley (Thesis advisor) / Sullivan, Amanda (Committee member) / Caterino, Linda C. (Committee member) / Arizona State University (Publisher)
Created2011
Description
The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) General Abilities Index (GAI) and Cognitive Proficiency Index (CPI) have been advanced as possible diagnostic markers of Attention-Deficit Hyperactivity Disorder (ADHD). Diagnostic utility statistics were used to test the ability of GAI-CPI difference scores to identify children with ADHD. Participants included an ADHD sample (n = 78), a referred but non-diagnosed hospital sample (n = 66), and a simulated sample with virtually identical psychometric characteristics as the WISC-IV 2,200 child standardization sample. Receiver Operating Characteristic (ROC) analyses were computed to determine the utility of GAI-CPI difference scores to identify children with ADHD. The GAI-CPI discrepancy method had an AUC of .64, 95% CI [0.58, 0.71] for the ADHD sample compared to the simulated normative sample and an AUC of .46, 95% CI [0.37, 0.56] for the ADHD sample compared to the referred but non-diagnosed hospital sample. These AUC scores indicate that the GAI-CPI discrepancy method has low accuracy.
ContributorsDevena, Sarah (Author) / Watkins, Marley W. (Thesis advisor) / Wodrich, David L (Committee member) / Sullivan, Amanda (Committee member) / Arizona State University (Publisher)
Created2010