Structure of the Wechsler Intelligence Scale for Children--Fourth Edition among a national sample of referred students

The structure of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV; D. Wechsler, 2003a) was analyzed via confirmatory factor analysis among a national sample of 355 students referred for psychoeducational evaluation by 93 school psychologists from 35 states. The structure of the WISC-IV core battery was best represented by four first-order factors as per D. Wechsler (2003b), plus a general intelligence factor in a direct hierarchical model. The general factor was the predominate source of variation among WISC-IV subtests, accounting for 48% of the total variance and 75% of the common variance. The largest 1st-order factor, Processing Speed, only accounted for 6.1% total and 9.5% common variance. Given these explanatory contributions, recommendations favoring interpretation of the 1st-order factor scores over the general intelligence score appear to be misguided.     

Replication of the factor structure of the Wechsler Adult Intelligence Scale--Third Edition with a Canadian sample

Exploratory and confirmatory factor analyses of the subtests of the Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997b) were conducted on a stratified sample of Canadian adults (n = 718). As was previously demonstrated for the children's version of this scale, the factor model of the American standardization sample was replicated across this Canadian national sample. Results of the factor analyses confirmed the presence of the 4 WAIS-III factors: Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed.     

Decreasing scoring errors on Wechsler Scale Vocabulary, Comprehension, and Similarities subtests: a preliminary study

Studies of graduate students learning to administer the Wechsler scales have generally shown that training is not associated with the development of scoring proficiency. Many studies report on the reduction of aggregated administration and scoring errors, a strategy that does not highlight the reduction of errors on subtests identified as most prone to error. This study evaluated the development of scoring proficiency specifically on the Wechsler (WISC-IV and WAIS-III) Vocabulary, Comprehension, and Similarities subtests during training by comparing a set of 'early test administrations' to 'later test administrations.' Twelve graduate students enrolled in an intelligence-testing course participated in the study. Scoring errors (e.g., incorrect point assignment) were evaluated on the students' actual practice administration test protocols. Errors on all three subtests declined significantly when scoring errors on 'early' sets of Wechsler scales were compared to those made on 'later' sets. However, correcting these subtest scoring errors did not cause significant changes in subtest scaled scores. Implications for clinical instruction and future research are discussed.     

Neuropsychological status of French children with developmental dyslexia and/or developmental coordination disorder: Are both necessarily worse than one?

Developmental dyslexia (DD) and developmental coordination disorder (DCD) co-occur frequently, raising the underlying question of shared etiological bases. We investigated the cognitive profile of children with DD, children with DCD, and children with the dual association (DD + DCD) to determine the inherent characteristics of each disorder and explore the possible additional impact of co-morbidity on intellectual, attentional, and psychosocial functioning. The participants were 8- to 12-year-olds (20 DD, 22 DCD, and 23 DD + DCD). Cognitive abilities were assessed by the Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) and the Continuous Performance Test – Second Edition (CPT-II) and behavioral impairments were evaluated by the Child Behavior Checklist (CBCL). No differences were found between the three groups on attention testing (CPT-II) or psychosocial characteristics (CBCL), but a higher percentage of DD + DCD children had pathological scores on psychosocial scales. Significant between-group differences were observed on Processing Speed Index scores and the block design and symbol search subtests, where DD children fared better than DCD children. No significant differences were evident between the co-morbid vs. the pure groups. Our results clearly show significant differences between children with DD only and children with DCD only. In particular, visuo-spatial disabilities and heterogeneity of intellectual profile seem to be good markers of DCD. However, it should be noted that despite these distinct and separate characteristics, a common cognitive profile (weaknesses and strengths) is likely shared by both neurodevelopmental disorders. Surprisingly, concerning co-morbidity, DD + DCD association is not associated with a decrease in intellectual or attentional capacities.     

Generalizability of WISC-IV index and subtest score profiles in children with traumatic brain injury

The Wechsler Intelligence Scale for Children, 4th edition (WISC-IV) is often used to assess children with traumatic brain injury (TBI); although limited information is available regarding its psychometric properties in these children. Two recent reports suggest that the Perceptual Reasoning Index is not uniquely sensitive to TBI, which differs from the Perceptual Organization Index of the WISC-III. The current study examined WISC-IV profiles in two independently gathered samples of children with TBI. Examination of profiles indicated similarities between the current findings and those reported in other studies, in that the greatest deficits were present on the Processing Speed Index and its component subtests of Coding and Symbol Search, while the Perceptual Reasoning index score was comparable to the Verbal Comprehension Index. Also, no significant index or subtest score differences were present when the current sample was compared to the children with TBI reported by Allen, Thaler, Donohue and Mayfield (2010 ). The present findings are consistent with two prior studies of the WISC-IV in children with TBI, providing additional evidence for profile differences between the WISC-III and WISC-IV. The results also suggest that WISC-IV profiles reported in prior studies are generalizable across TBI samples and study sites.     

Substituing supplementary subtests for core subtests on reliability of WISC-IV Indexes and Full Scale IQ

The effects of replacing core subtests with supplementary subtests on composite score reliabilities were evaluated for the WISC-IV Indexes and Full Scale IQ. When Wechsler's guidelines are followed, i.e., only one substitution for each Index; no more than two substitutions from different Indexes when assessing the Full Scale IQ, summary score reliabilities remain high, and measurement error, as defined by confidence intervals around obtained scores, never increases by more than 1 index score point. In three instances, substitution of a supplementary subtest for a core subtest actually increased the reliabilities and decreased the amount of associated measurement error.     

Indice d’aptitude général pour le WISC-IV : normes francophones

The Wechsler Children Intelligence Scale–Fourth Edition (WISC-IV, 2005) allows to calculate the FSIQ and four index scores: verbal comprehension, perceptual reasoning, working memory, and processing speed. In 1998, Prifitera and colleagues recommended to calculate the General Ability Index (GAI), as an alternative composite score. This score is based on Verbal Comprehension and Perceptual Reasoning only. The objective of the first study presented in this paper is to provide the GAI normative tables for the French WISC-IV; these tables were created using a statistical approximation procedure. The objective of the second study is to test the validity of these tables with data obtained from 60 children. Correlation between FSIQ and GAI is 0.91 and the relative mean difference is only 0.18 point. These tables, for the French version of the WISC-IV, allow using the GAI as an alternative measure of general ability.     

Development of demographic norms for four new WAIS-III/WMS-III indexes

Following the publication of the third edition Wechsler scales (i.e., WAIS-III and WMS-III), demographically corrected norms were made available in the form of a computerized scoring program (i.e., WAIS-III/WMS-III/WIAT-II Scoring Assistant). These norms correct for age, gender, ethnicity, and education. Since then, four new indexes have been developed: the WAIS-III General Ability Index, the WMS-III Delayed Memory Index, and the two alternate Immediate and Delayed Memory Indexes. The purpose of this study was to develop demographically corrected norms for the four new indexes using the standardization sample and education oversample from the WAIS-III and WMS-III. These norms were developed using the same methodology as the demographically corrected norms made available in the WAIS-III/WMS-III/WIAT-II Scoring Assistant.     

Education-stratified base-rate information on discrepancy scores within and between the Wechsler Adult Intelligence Scale--Third Edition and the Wechsler Memory Scale--Third Edition

The Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997a) and the Wechsler Memory Scale--Third Edition (WMS-III; D. Wechsler, 1997b) are 2 of the most frequently used measures in psychology and neuropsychology. To facilitate the diagnostic use of these measures in the clinical decision-making process, this article provides information on education-stratified, directional prevalence rates (i.e., base rates) of discrepancy scores between the major index scores for the WAIS-III, the WMS-III, and between the WAIS-III and WMS-III. To illustrate how such base-rate data can be clinically used, this article reviews the relative risk (i.e., odds ratio) of empirically defined "rare" cognitive deficits in 2 of the clinical samples presented in the WAIS-III--WMS-III Technical Manual (The Psychological Corporation, 1997).     

The WISC-V in children and adolescents with epilepsy

Despite its popularity in the neuropsychological evaluation of children, the utility of the Wechsler Intelligence Scale for Children – Fifth Edition (WISC-V) has not yet been investigated in children with epilepsy. Eighty clinically referred children and adolescents with epilepsy were administered the WISC-V as part of a comprehensive assessment and scores were compared to matched controls from the WISC-V standardization sample. T tests compared WISC-V indices and subtests between patients and controls and Chi-square analyses compared the rates of low scores. Correlational analyses assessed the relationships between epilepsy severity variables (e.g., age of onset, duration of epilepsy, number of antiepileptic drugs, seizure frequency). All WISC-V composites and subtests were significantly lower in patients versus controls and the rate of low scores was higher in patients than controls for all composites and subtests with the exception of Figure Weights. The Working Memory Index and Processing Speed Index were most sensitive to impairment, while the Verbal Comprehension Index and Fluid Reasoning Index were least sensitive. Of the epilepsy severity variables, age of seizure onset and number of antiepileptic drugs were strong predictors of deficits, whereas seizure frequency was the weakest predictor. Importantly, no significant differences were seen in children with right hemisphere epilepsy versus left on the five WISC-V composites, though a trend was seen towards a lower Visual-Spatial Index in those with right-sided focal seizures.     

Confirmatory factor analyses of the WAIS-III standardization data

Confirmatory factor analyses with the standardization data of the Wechsler Adult Intelligence Scale-Third Edition (Wechsler, 1997a) compared 6 models with 1 to 4 factors for 11- and 13-subtest versions of the test. Three factors usually fit the data better than 2 factors, but 2-factor models were more parsimonious. A 2-factor model with a Verbal Comprehension factor (Vocabulary, Similarities, Information, and Comprehension) was as good as and sometimes better than the 2-factor model defined by the traditional separation of Verbal and Performance subtests. For 3-factor models, alternative specifications of processing speed subtests on either the Perceptual Organization or Freedom From Distractibility factor were comparable, and specifying a 4th factor for Digit Symbol and Symbol Search had little advantage in comparison with 3-factor models with correlated errors for the 2 subtests.     

Development of an eight-subtest short form of the WISC-IV and evaluation of its clinical utility in children with traumatic brain injury

This study evaluated the degree to which an 8-subtest short form of the Wechsler Intelligence Scale for Children—Fourth Edition would yield acceptable estimates of the long-form Full-Scale IQ index while clarifying the underlying factor structure in a sample of 100 children and adolescents with traumatic brain injury. The short-form Full-Scale IQ had sufficient (i.e., at least two thirds) nonerror covariance with its full-length counterpart. In addition, a sufficient proportion (i.e., > 80%) of these short-form estimates fell within the 90% confidence interval of the respective full-length scores. Importantly, the elimination of 2 subtests, and in particular the Picture Concepts subtest, resulted in a factor structure where each remaining subtest was fairly specifically associated with its intended scale. It is concluded that this short form can be used clinically in children with traumatic brain injury without sacrificing reliability and with more straightforward interpretability at the level of the factor index scores.     

WAIS-IV subtest covariance structure: conceptual and statistical considerations

D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning, and Processing Speed) but also revealed unexplained covariance between Block Design and Visual Puzzles (Perceptual Reasoning subtests). That covariance was not included in the final models. Instead, a path was added from Working Memory to Figure Weights (Perceptual Reasoning subtest) to improve fit and achieve a desired factor pattern. The present research with the same data (N = 1,800) showed that the path from Working Memory to Figure Weights increases the association between Working Memory and Matrix Reasoning. Specifying both paths improves model fit and largely eliminates unexplained covariance between Block Design and Visual Puzzles but with the undesirable consequence that Figure Weights and Matrix Reasoning are equally determined by Perceptual Reasoning and Working Memory. An alternative 4-factor model was proposed that explained theory-implied covariance between Block Design and Visual Puzzles and between Arithmetic and Figure Weights while maintaining compatibility with WAIS-IV Index structure. The proposed model compared favorably with a 5-factor model based on Cattell-Horn-Carroll theory. The present findings emphasize that covariance model comparisons should involve considerations of conceptual coherence and theoretical adherence in addition to statistical fit.     

WISC-IV and WISC-III profiles in children with ADHD

Wechsler Intelligence Scale for Children, 3rd and 4th editions (WISC-III n = 586 and WISC-IV n = 118), profiles were compared for children with ADHD and normal intelligence. Mean Verbal Comprehension Index (VCI) and Perceptual Organization/Perceptual Reasoning Index (POI/PRI) scores were significantly higher than Freedom From Distractibility/Working Memory Index (FDI/WMI) and Processing Speed Index (PSI), and Symbol Search was higher than Coding. FDI/WMI and PSI scores were similar on both tests, but VCI and POI/PRI were higher on the WISC-IV than on the WISC-III. Therefore, index discrepancies were greater for the WISC-IV, suggesting that the WISC-IV might be better than the WISC-III in delineating the strengths and weaknesses of children with ADHD. All children in the WISC-IV sample scored lowest on WMI or PSI, whereas only 88% of the WISC-III children scored lowest on FDI or PSI. Thus, the WISC-IV may be more helpful in diagnosing ADHD than the WISC-III.     

Spoken Narrative Assessment: A Supplementary Measure of Children’s Creativity

This study developed a spoken narrative (i.e., storytelling) assessment as a supplementary measure of children’s creativity. Both spoken and gestural contents of children’s spoken narratives were coded to assess their verbal and nonverbal creativity. The psychometric properties of the coding system for the spoken narrative assessment were investigated with 30 Cantonese-speaking children aged six to nine. The internal consistency and the intercoder agreement were good. In addition, children’s scores on the 3 coded variables were moderately correlated with their creativity-relevant skills as measured by Alternate Uses Task (Guilford, 1967) and subjective ratings of creativity provided by judges. Children with higher verbal skills, as measured by Similarities (The Wechsler Intelligence Scale for Children – 4th Edition (Hong Kong); WISC-IV HK), also scored higher in the speech composite of the coding system. The findings showed that the coding system of the spoken narrative assessment is reliable and valid for measuring children’s creativity objectively. An age-related norm will be established in future.     

The mediating role of cognitive ability on the relationship between motor proficiency and early academic achievement in children

The aim of this study was to examine the relationship between motor proficiency and academic achievement in 7 years-old children. A mediating model in which the relation between motor proficiency and academic achievement is mediated by cognitive ability was tested. Participants included 152 children from the longitudinal study Jeunes enfants et leurs milieux de vie (Young Children and their Environments). Motor proficiency was evaluated with the Bruininks-Oseretsky Test of Motor Proficiency (BOT2), cognitive ability with the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) and academic achievement with the Wechsler Individual Achievement Test II (WIAT II). Results showed that motor proficiency, cognitive ability and academic achievement were positively correlated with each other. A structural equation modeling analysis revealed that motor proficiency had a positive effect on academic achievement through an indirect path via cognitive ability. These results highlight the fundamental importance of motor skills in children's academic achievement in early school years.     

Measurement invariance of WISC-IV across normative and clinical samples

Measurement invariance of the WISC-IV second-order factorial structure between normative and clinical samples was investigated using WISC-IV core subtests and a total of 1100 children aged 6-16. Multi-group higher order analysis of mean and covariance structure (MG-MACS) models were used to analyze these data. Results supported measurement invariance. Only Coding and Comprehension subtest intercepts varied slightly between groups. The hypothesized WISC-IV factor model described the data well. Factor patterns, first- and second-order factor loadings, intercepts, residual variances of measured subtests, and disturbances of first-order factors of the WISC-IV were generally invariant. Results suggested that WISC-IV index scores and subtests have the same meaning for children in both normative and clinical groups.     

An independent examination of the equivalence of the standard and digital administration formats of the Wechsler Intelligence Scale for Children-5th Edition

A new administration format for the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V; Wechsler, 2014) was introduced in 2016 on Q-interactive, Pearson's digital platform for test administration and scoring. The current study examined the measurement unit equivalence of the WISC-V standard and digital administration formats using counter-balanced administration of the 10 primary subtests to measure intellectual ability. The results indicated that correlations (r) between standard scores on subtests and composites administered in each format were generally moderate, with mean rs of 0.64 for subtests and 0.71 for composites after correction for attenuation, with the lowest rs for processing speed. Split-plot ANOVAs were conducted to examine within-subjects main effects for administration format and order and their interaction. The results of these analyses revealed significant main effects for format for the Full Scale IQ and Processing Speed composite scores, with small to medium effect sizes (ds > 0.40). These format effects largely stemmed from the non-equivalence of the Coding subtest, which is used to derive both composites. For Coding, the main effect for format was statistically significant, with a large effect size (d = 0.69). Statistically significant administration order by format interaction effects were also observed for a number of composites and subtests, with medium to large effect sizes (ƞ_ps² > 0.20). In each case, higher mean scores were observed when the WISC-V was administered first in digital format. Implications of these results for research and practice are discussed.     

Factor invariance between genders on the Wechsler Intelligence Scale for Children–Fifth Edition

This study investigated the factorial invariance of the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) between samples of male and female children. A higher-order 5-factor model was tested on a nationally-representative sample of 2200 children aged 6 to 16 years. The results demonstrated full factorial invariance between genders. The WISC-V subtests demonstrate the same underlying theoretical latent constructs, the same strength of relationships among factors and subtests, the same validity of each first-order factor, and the same communalities, regardless of the gender, thus supporting the same interpretive approach and meaningful comparisons of the WISC-V between male and female children.