FACTOR STRUCTURE OF THE WECHSLER INTELLIGENCE SCALES FOR CHILDREN-FOURTH EDITION AMONG REFERRED NATIVE AMERICAN STUDENTS

Neurodevelopmental profiles of 4-year-olds in the Navajo Birth Cohort Study

Objective

Native American children disproportionally face many risk factors for poor developmental outcomes; these factors include poverty, environmental toxicant exposure, and limited medical, and intervention services. To understand these risks, comprehensive documentation of developmental and behavioral phenotypes are needed. In the current descriptive study, we assessed the neurodevelopment of young Diné (Navajo) children using standardized assessment instruments in combination with expert clinician judgment.

Methods

As part of an ongoing, population-based, prospective birth cohort study, we conducted comprehensive neurodevelopmental assessments of 138, 3-5-year-old, Diné children residing on or near the Navajo Nation. We report results from standardized parent reports, psychiatric examinations, and direct assessments of children's language, cognitive, adaptive, and social-emotional development, as well as best estimate clinical diagnoses.

Results

Forty-nine percent of our sample met DSM-5 criteria for a neurodevelopmental disorder (NDD) diagnosis. Language and speech sound disorders were most common, although autism spectrum disorder (ASD) was also elevated compared to the general population. Though language performance was depressed amongst all groups of children with, and without, NDDs, those meeting criteria for certain NDDs performed significantly lower on all language measures, when compared to those without. Social-emotional, behavioral, and nonverbal cognitive ability were in the average range overall.

Conclusions

Diné children in our study were found to have a high percentage of clinically significant developmental delays. Overall, children presented with a pervasive pattern of depressed language performance across measures, irrespective of diagnosis (or no diagnosis), while other domains of functioning were similar to normative samples. Findings support the need to identify appropriate intervention and educational efforts for affected youth, while also exploring the causes of the specific developmental delays. However, longitudinal studies are necessary to establish best practices for identifying delays and delineating resilience factors to optimize development of Diné children.

Introduction to the Special Issue–School psychology and Indigenous Peoples: Critical Perspectives and Indigenous-led Approaches

This issue of the Canadian Journal of School Psychology is the first of two parts of a special issue devoted to the intersection of school psychology and Indigenous Peoples within the Canadian context. Given the limited existing literature that is squarely focused on this intersection, the articles in these two issues are collectively a substantive academic contribution to school psychology educators, practitioners, researchers, and students. These articles challenge mainstream practice, training, ethics, and intervention approaches within school psychology, while also describing exemplary collaborations with Indigenous communities and advancements in Indigenizing and decolonizing school psychology training and practice.

A Systematic Review of Indigenous Representation in School Psychology Research

Indigenous youth comprise a significant and diverse collection of populations. School psychologists are uniquely placed to serve Indigenous students and improve their long-term outcomes. However, in the face of longstanding colonial practices and systemic oppression, which have resulted in poor educational outcomes for Indigenous students, school psychology research broadly underrepresents Indigenous students. This proves problematic considering research informs practice. The goal of this review is to evaluate the current standing of school psychology research focused on Indigenous youth and identify areas of need. The current systematic review yielded 57 articles focusing on Indigenous youth from 10 indexed school psychology journals. A significant portion of the articles were published in the 1980s, with fewer than three publications per year in the two decades following. The articles demonstrated a preference for assessment and related topics, with limited research focused on intervention, culture, and equity. This focus on assessment to compare Indigenous youth with youth of other racial and ethnic backgrounds serves to support the systems of oppression in place. These findings highlight the need for school psychology research to exert a concentrated effort toward Indigenous-focused research with more varied topics beyond assessment. Implications for trainers, researchers, and school psychology journals 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.

Structural Validity of the WISC-IV for Students With ADHD

OBJECTIVE

To evaluate the structural validity of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV).

METHOD

Confirmatory factor analyses were applied to a sample of 233 students diagnosed with ADHD by school multidisciplinary evaluation teams to evaluate the relative fit of the following competing models: (a) one factor, (b) two oblique verbal and nonverbal factors, (c) three oblique verbal, perceptual, and combined working memory/processing speed factors, (d) four oblique verbal, perceptual, working memory, and processing speed factors, (e) a higher-order model with four first-order factors, and (f) a bifactor model with four domain-specific factors.

RESULTS

A higher-order four-factor model fit the data best, which was composed of a general intelligence factor and four domain-specific factors that matched the four factors specified in the WISC-IV technical and interpretive manual. Moreover, the general intelligence factor explained more than two times the total variance contributed by all four domain-specific factors combined.

CONCLUSIONS

Results substantiate previous research on the WISC-IV, indicating that the general intelligence factor contributes the most reliable information. Consequently, it is recommended that interpretation of the WISC-IV remain at the Full-Scale IQ score level.

Structure of the Wechsler Intelligence Scale for Children - Fourth Edition in a Group of Children with ADHD

Objective: This study used confirmatory factor analysis to examine the factor structure for the 10 core WISC–IV subtests in a group of children (N = 812) with ADHD.

Method: The study examined oblique four- and five-factor models, higher order models with one general secondary factor and four and five primary factors, and a bifactor model with a general factor and four specific factors.

Results: The findings supported all models tested, with the bifactor model being the optimum model. For this model, only the general factor had high explained common variance and omega hierarchical value, and it predicted reading and arithmetic abilities.

Conclusion: The findings favor the use of the FSIQ scores of the WISC-IV, but not the subscale index scores.

Structural Validity of the WISC-IV for Students With Learning Disabilities

The structural validity of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was evaluated using confirmatory factor analysis for a clinical sample of 1,537 students diagnosed with specific learning disabilities (SLD) by school psychologists in two large southwestern school districts. Results indicated that a bifactor model consisting of four first-order domain specific factors and a general intelligence breadth factor fit the data best. Consequently, the structural validity of the WISC-IV for students with SLD was supported by the results of the present study. The general intelligence factor contributed the most information, accounting for 48% of the common variance. Given this structure, it was recommended that score interpretation should emphasize the Full-Scale IQ score because of the marginal contributions of the first-order domain-specific factors and their low precision of measurement independent of the general factor.