Reliability and factorial validity of the Canadian Wechsler Intelligence Scale for Children–Fifth Edition

Measurement Invariance of the WISC-V across a Clinical Sample of Children and Adolescents with ADHD and a Matched Control Group

Measurement invariance of the Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) 10-primary subtest battery was analyzed across a group of children and adolescents with ADHD (n = 91) and a control group (n = 91) matched by sex, age, migration background, and parental education or type of school. First, confirmatory factor analyses (CFAs) were performed to establish the model fit for the WISC-V second-order five-factor model in each group. A sufficiently good fit of the model was found for the data in both groups. Subsequently, multigroup confirmatory factor analyses (MGCFAs) were conducted to test for measurement invariance across the ADHD and control group. Results of these analyses indicated configural and metric invariance but did not support full scalar invariance. However, after relaxing equality constraints on the Vocabulary (VC), Digit Span (DS), Coding (CD), Symbol Search (SS), and Picture Span (PS) subtest intercepts as well as on the intercepts of the first-order factors Working Memory (WM) and Processing Speed (PS), partial scalar invariance could be obtained. Furthermore, model-based reliability coefficients indicated that the WISC-V provides a more precise measurement of general intelligence (e.g., represented by the Full-Scale IQ, FSIQ) than it does for cognitive subdomains (e.g., represented by the WISC-V indexes). Group comparisons revealed that the ADHD group scored significantly lower than the control group on four primary subtests, thus achieving significantly lower scores on the corresponding primary indexes and the FSIQ. Given that measurement invariance across the ADHD and the control group could not be fully confirmed for the German WISC-V, clinical interpretations based on the WISC-V primary indexes are limited and should only be made with great caution regarding the cognitive profiles of children and adolescents with ADHD.

Right Superior Frontal Gyrus Cortical Thickness in Pediatric ADHD

OBJECTIVE

We investigated the right Superior Frontal Gyrus (right-SFG) and Anterior Cingulate Cortex (ACC) in children with ADHD and their clinical relevance with Executive Function (EF) and ADHD symptom severity.

METHODS

About 26 children with ADHD and 24 typically developing children (TDC; 7‒16 years) underwent Magnetic Resonance Imaging (MRI) and completed an EF assessment battery.

RESULTS

Significantly thinner right-SFG in the ADHD group was found compared to the TDC group (t (48) = 2.81, p = .007, Cohen's d = 0.84). Linear regression models showed that 12.5% of inattention, 13.6% of hyperactivity, and 9.0% of EF variance was accounted for by the right-SFG thickness.

CONCLUSIONS

Differences in the right-SFG thickness were found in our ADHD group and were associated with parent ratings of inattentive and hyperactive symptoms as well with EF ratings. These results replicate previous findings of thinner right-SFG and are consistent with the delayed cortical maturation theory of ADHD.

Differences in Parents and Teachers' Perceptions of Behavior Manifested by Gifted Children with ADHD Compared to Gifted Children without ADHD and Non-Gifted Children with ADHD Using the Conners 3 Scale

The potential for the misdiagnosis of giftedness as attention deficit/hyperactivity disorder (ADHD) has been well documented, as has the clinical diagnostic profile of individuals with both giftedness and ADHD. This study aimed to examine parents' and teachers' responses to the Conners 3 behavioral rating scale of gifted students with ADHD compared to gifted students without ADHD and non-gifted students with ADHD. Ninety-two children aged 6 to 16 years were included in the study. On the basis of clinical assessments utilizing the K-SADS, the WISC-V, and other neurocognitive tests, the students were split into three groups: gifted/ADHD (n = 35), ADHD (n = 35), and gifted (n = 22). The results revealed that mothers', fathers', and teachers' responses to the Conners 3 rating scale distinguished well between the gifted group and the other two groups, but not between the gifted/ADHD and ADHD groups. The learning difficulties observed by teachers was the most significant element that distinguished gifted/ADHD students from non-gifted ADHD students. Other results indicated that mothers and fathers reported more inattention problems in their gifted/ADHD children than teachers. Additionally, mothers tended to observe more learning and executive function problems in their gifted/ADHD children than teachers did. These findings highlight the importance of multiple informants complementing each other in the assessment process for ADHD in a gifted context to counteract the masking effect between giftedness and ADHD.

Impact of stimulant medication on behaviour and executive functions in children with attention-deficit/hyperactivity disorder

BACKGROUND

Children with attention-deficit/hyperactivity disorder (ADHD) often exhibit behaviour challenges and deficits in executive functions (EF). Psychostimulant medications [e.g., methylphenidate (MPH)] are commonly prescribed for children with ADHD and are considered effective in 70% of the cases. Furthermore, only a handful of studies have investigated the long-term impact of MPH medication on EF and behaviour.

AIM

To evaluate behaviour and EF challenges in children with ADHD who were involved in an MPH treatment trial across three-time points.

METHODS

Thirty-seven children with ADHD completed a stimulant medication trial to study the short- and long-term impact of medication. Children with ADHD completed three neuropsychological assessments [Continuous Performance Test (CPT)-II, Digit Span Backwards and Spatial Span Backwards]. Parents of children with ADHD completed behaviour rating scales [Behaviour Rating Inventory of Executive Functioning (BRIEF) and Behaviour Assessment System for Children-Second Edition (BASC-2)]. Participants were evaluated at: (1) Baseline (no medication); and (2) Best-dose (BD; following four-week MPH treatment). Additionally, 18 participants returned for a long-term naturalistic follow up (FU; up to two years following BD).

RESULTS

Repeated measure analyses of variance found significant effects of time on two subscales of BRIEF and four subscales of BASC-2. Neuropsychological assessments showed some improvement, but not on all tasks following the medication trial. These improvements did not sustain at FU, with increases in EF and behaviour challenges, and a decline in performance on the CPT-II task being observed.

CONCLUSION

Parents of children with ADHD reported improvements in EF and behaviours during the MPH trial but were not sustained at FU. Combining screening tools and neuropsychological assessments may be useful for monitoring medication responses.

Factor structure of the new Scandinavian WISC-V version: Support for a five-factor model

The fifth version of Wechsler Intelligence Scale for Children is designed to measure five distinct aspects of intelligence, incorporating a new fluid reasoning index to the four indexes of the previous fourth version. Several factor analyses, however, have failed to support the fifth factor. The Scandinavian version is the only national version not showing clear superiority for the five-factor solution in the Manual. In the present study, we analyze WISC-V protocols from a clinical sample of 237 children tested with the new Scandinavian version. We perform six confirmatory factor analyses (CFA) testing three hierarchical-, two bifactor-, and one correlated candidate factor models. The study shows that the three-factor model does not fit the data, and that all four- and five-factor models showed good fit. The four-factor bifactor model was somewhat better than the five-bifactor and hierarchical models, but the correlated five-factor model was the superior model. Finding support for five-factors in a clinical sample representative of those most probable to be tested with the test, strengthen the claim that also the Scandinavian version measure a distinct fluid factor as intended by the test owners, and thus that clinicians may use the index scores as their main level of analysis. Review of previous CFAs show that the choice of statistical methods for CFA, bifactor or hierarchical/correlated, influence whether second order factor models are better than g-factor models.

Revisiting the Factor Structure of the German WISC-V for Clinical Interpretability: An Exploratory and Confirmatory Approach on the 10 Primary Subtests

With the exception of a recently published study and the analyses provided in the test manual, structural validity is mostly uninvestigated for the German version of the Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V). Therefore, the main aim of the present study was to examine the latent structure of the 10 WISC-V primary subtests on a bifurcated extended population-representative German standardization sample (N=1,646) by conducting both exploratory (EFA; n=823) and confirmatory (CFA; n=823) factor analyses on the original data. Since no more than one salient subtest loading could be found on the Fluid Reasoning (FR) factor in EFA, results indicated a four-factor rather than a five-factor model solution when the extraction of more than two suggested factors was forced. Likewise, a bifactor model with four group factors was found to be slightly superior in CFA. Variance estimation from both EFA and CFA revealed that the general factor dominantly accounted for most of the subtest variance and construct reliability estimates further supported interpretability of the Full Scale Intelligence Quotient (FSIQ). In both EFA and CFA, most group factors explained rather small proportions of common subtest variance and produced low construct replicability estimates, suggesting that the WISC-V primary indexes were of lower interpretive value and should be evaluated with caution. Clinical interpretation should thus be primarily based on the FSIQ and include a comprehensive analysis of the cognitive profile derived from the WISC-V primary indexes rather than analyses of each single primary index.

Exploratory Factor Analyses of the French WISC-V (WISC-VFR) for Five Age Groups: Analyses Based on the Standardization Sample

This study investigated the factor structure of the French Wechsler Intelligence Scale for Children–Fifth Edition with five standardization sample age groups (6-7, 8-9, 10-11, 12-13, 14-16 years) using hierarchical exploratory factor analysis followed by Schmid–Leiman procedure. The primary research questions included (a) how many French Wechsler Intelligence Scale for Children–Fifth Edition factors should be extracted and retained in each age subgroup, (b) how are subtests associated with the latent factors, (c) was there evidence for the publisher’s claim of five first-order factors and separate Visual Spatial and Fluid Reasoning factors, (d) what proportion of variance was due to general intelligence versus the first-order group ability factors following a Schmid–Leiman procedure, and (e) do results support the age differentiation hypothesis? Results suggested that four factors might be sufficient for all five age groups and results did not support the distinction between Visual Spatial and Fluid Reasoning factors. While the general factor accounted for the largest portions of variance, the four first-order factors accounted for small unique portions of variance. Results did not support the age differentiation hypothesis because the number of factors remained the same across age groups, and there was no change in the percentage of variance accounted for by the general factor across age groups.

Examination of five- and four-subtest short form IQ estimations for the Wechsler Intelligence Scale for Children-Fifth edition (WISC-V) in a mixed clinical sample

Evaluating general cognitive ability (i.e., intelligence) is common in neuropsychological practice, and identifying abbreviated assessments of intelligence is often advantageous. Despite the Wechsler Intelligence Scale for Children, Fifth Edition's (WISC-V) widespread contemporary use, limited research has identified clinically useful short form (SF) full scale IQ (FSIQ) estimations in clinical samples. This study sought to address this gap in the literature. Two hundred sixty-eight pediatric participants (M age = 9.79; 69% male; 88% Caucasian/White) who underwent psychological/neuropsychological evaluation were included. Mean scores for WISC-V scores fell in the low average-to-average ranges, consistent with the clinical nature of this sample (e.g., M FSIQ = 85.3). Ten unique SF combinations with five (pentad) and four (tetrad) subtests, each intentionally selected to represent a breadth of domains subsumed by WISC-V FSIQ, were described by summing subtest age-corrected scaled scores. Regression-based and prorated FSIQ estimates were calculated, and mean differences suggested some prorated estimates should be arithmetically adjusted. Both regression-based and prorated/adjusted methods provided FSIQ estimates that were accurate within five Standard Score points of true FSIQ for approximately 81-92% (pentad) and 65-76% (tetrads) of participants. Prorated/adjusted estimates appeared to provide somewhat better accuracy than regression-based estimates. Relationships between SFs and true FSIQ did not appear to be moderated by participant age, gender, nor how many WISC-V subtests were administered to participants within this archival sample (i.e., 7 vs. 10). Implications of these findings, including benefits, detriments, and other considerations of each SF combination, in addition to limitations of this study, are discussed in detail.

Use of translated and adapted versions of the WISC-V: Caveat emptor

The Wechsler Intelligence Scale for Children (WISC) is the most widely used intelligence test in the world. Now in its fifth edition, the WISC-V has been translated and adapted for use in nearly a dozen countries. Despite its popularity, numerous concerns have been raised about some of the procedures used to develop and validate translated and adapted versions of the test around the world. The purpose of this article is to survey the most salient of those methodological and statistical limitations. In particular, empirical data are presented that call into question the equating procedures used to validate the WISC-V Spanish, suggesting cautious use of that instrument. It is believed that the issues raised in the present article will be instructive for school psychologists engaged in the clinical assessment of intelligence with the WISC-V Spanish and with other translated and adapted versions around the world.

Monte Carlo Modeling of Contemporary Intelligence Test (IQ) Factor Structure: Implications for IQ Assessment, Interpretation, and Theory

Researchers continue to debate the constructs measured by commercial ability tests. Factor analytic investigations of these measures have been used to develop and refine widely adopted psychometric theories of intelligence particularly the Cattell-Horn-Carroll (CHC) model. Even so, this linkage may be problematic as many of these investigations examine a particular instrument in isolation and CHC model specification across tests and research teams has not been consistent. To address these concerns, the present study used Monte Carlo resampling to investigate the latent structure of four of the most widely used intelligence tests for children and adolescents. The results located the approximate existence of the publisher posited CHC theoretical group factors in the Differential Abilities Scales-Second edition and the Kaufman Assessment Battery for Children-Second edition but not in the Wechsler Intelligence Scale for Children-Fifth edition or the Woodcock-Johnson IV Tests of Cognitive Abilities. Instead, the results supported alternative conceptualizations from independent factor analytic research. Additionally, whereas a bifactor model produced superior fit indices in two instruments (Wechsler Intelligence Scale for Children-Fifth edition and Woodcock-Johnson IV Tests of Cognitive Abilities), a higher order structure was found to be superior in the Kaufman Assessment Battery for Children-Second edition and the Differential Abilities Scales-Second edition. Regardless of the model employed, the general factor captured a significant portion of each instrument's variance. Implications for IQ test assessment, interpretation, and theory are discussed.

Measurement Invariance Across Gender on the Second-Order Five-Factor Model of the German Wechsler Intelligence Scale for Children-Fifth Edition

The present study investigated measurement invariance across gender on the German Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V). The higher order model that was preferred by the test publishers was tested on a population-representative German sample of 1,411 children and adolescents aged between 6 and 16 years. Confirmatory factor analyses were conducted to test for measurement invariance. As soon as partial scalar invariance could be established by freeing nonequivalent subtest intercepts, results demonstrated that 11 out of 15 subtest scores have the same meaning for male and female children. These findings support interpretable comparisons of the WISC-V test scores between males and females but only in due consideration of partial scalar invariance and with respect to the underlying factor structure. Despite this, however, results did not support the overall structural validity of the higher order model. Thus, replacing the former Perceptual Reasoning factor by Fluid Reasoning and Visual Spatial may be considered inappropriate due to the redundancy of the FRI as a separate factor. Results also indicated that the WISC-V provides stronger measurement of general intelligence (Full Scale IQ) than measurements of cognitive subdomains (WISC-V indexes). Interpretative emphasis should thus be placed on the Full Scale IQ rather than the WISC-V indexes.

Exploratory Factor Analyses of the Intelligence and Development Scales-2: Implications for Theory and Practice

The factor structure of the intelligence and scholastic skills domains of the Intelligence and Development Scales-2 was examined using exploratory factor analyses with the standardization and validation sample (N = 2,030, aged 5 to 20 years). Results partly supported the seven proposed intelligence group factors. However, the theoretical factors Visual Processing and Abstract Reasoning as well as Verbal Reasoning and Long-Term Memory collapsed, resulting in a five-factor structure for intelligence. Adding the three scholastic skills subtests resulted in an additional factor Reading/Writing and in Logical-Mathematical Reasoning showing a loading on abstract Visual Reasoning and the highest general factor loading. A data-driven separation of intelligence and scholastic skills is not evident. Omega reliability estimates based on Schmid-Leiman transformations revealed a strong general factor that accounted for most of the true score variance both overall and at the group factor level. The possible usefulness of factor scores is discussed.

Construct Validity of the WISC-V in Clinical Cases: Exploratory and Confirmatory Factor Analyses of the 10 Primary Subtests

Independent exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) research with the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) standardization sample has failed to provide support for the five group factors proposed by the publisher, but there have been no independent examinations of the WISC-V structure among clinical samples. The present study examined the latent structure of the 10 WISC-V primary subtests with a large (N = 2,512), bifurcated clinical sample (EFA, n = 1,256; CFA, n = 1,256). EFA did not support five factors as there were no salient subtest factor pattern coefficients on the fifth extracted factor. EFA indicated a four-factor model resembling the WISC-IV with a dominant general factor. A bifactor model with four group factors was supported by CFA as suggested by EFA. Variance estimates from both EFA and CFA found that the general intelligence factor dominated subtest variance and omega-hierarchical coefficients supported interpretation of the general intelligence factor. In both EFA and CFA, group factors explained small portions of common variance and produced low omega-hierarchical subscale coefficients, indicating that the group factors were of poor interpretive value.