Construct validity of the WISC–IV Italian edition: A bifactor examination of the standardization sample: Chi niente sa, di niente dubita

ABSTRACT

This study utilized confirmatory factor analyses to examine the latent factor structure of the Wechsler Intelligence Scale for Children–Fourth Edition, Italian adaptation (WISC–IV Italian) standardization sample. One through five, oblique first-order factor models and higher-order as well as bifactor models were examined and compared using CFA. The bifactor model provided the best explanation of the scale’s factor structure. Across all models, general intelligence accounted for the largest amount of explained common variance, with group factors accounting for nonsignificant and trivial amounts of explained common variance. Omega-hierarchical subscale coefficients indicated that unit-weighted composites that would be generated by group factors would contain miniscule unique variance and therefore be of little clinical utility. Results are consistent with numerous empirical studies examining other European adaptations of the instrument and are at odds with the model put forward by the publisher. Clinicians who use the WISC–IV Italian adaptation are warned against attempting to interpret factor index scores independent of general intelligence.

KEYWORDS:

• WISC–IV Italian
• confirmatory factor analysis
• bifactor analysis
• structural validity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Joseph C. Kush

Joseph C. Kush, Ph.D. is a Fulbright Scholar and Professor of Education at Duquesne University in Pittsburgh, PA. He serves on the editorial boards of several school psychology and assessment journals. His research interests include topics related to intellectual assessment and issues of test bias and test fairness for children from minority backgrounds. He is also strongly committed to issues of social justice. He is an accomplished guitarist and uses McIntosh computers exclusively.

Gary L. Canivez

Gary L. Canivez is Professor of Psychology at Eastern Illinois University principally involved in the Specialist in School Psychology program. Dr. Canivez is a Fellow of the American Psychological Association Division of Quantitative and Qualitative Methods, a Charter Fellow of the Midwestern Psychological Association, a member of the Society for the Study of School Psychology, and past president of the Arizona Association of School Psychologists. He is an Associate Editor for Archives of Scientific Psychology and is an editorial board member for several school psychology and assessment journals. His research interests are in applied psychometrics in evaluating psychological and educational tests (including international applications); and empirically supported test interpretation.