Confirmatory Factor Analysis of WAIS-IV in a Clinical Sample: Examining a Bi-Factor Model.

Rachel Collinson,Steven Muncer,Geoff Hill,Miranda Wheeler,Stephen Evans,Don Brechin,Jenna Moffitt

doi:10.3390/jintelligence5010002

Abstract

There have been a number of studies that have examined the factor structure of the Wechsler Adult Intelligence Scale IV (WAIS-IV) using the standardization sample. In this study, we investigate its factor structure on a clinical neuropsychology sample of mixed aetiology. Correlated factor, higher-order and bi-factor models are all tested. Overall, the results suggest that the WAIS-IV will be suitable for use with this population.

Highlights

The Wechsler Adult Intelligence Scale-IV (WAIS-IV) [1] incorporates significant structural and content revisions in comparison to the WAIS-III [2]
All three Perceptual Reasoning Index subtests from the Wechsler Adult Intelligence Scale IV (WAIS-IV) (i.e. Block Design, Matrix Reasoning, and Visual Puzzles (VP)) were administered. This requirement was due to the data being collected as part of a broader project looking into the validity and reliability of the new Visual Puzzles subtest in the WAIS battery
The difference in Tucker Lewis Index (TLI) between the bi-factor and higher-order factor model is 0.022, which is higher than the suggested threshold for indication of a practical improvement in models of 0.01 [10]

Summary

Introduction

The Wechsler Adult Intelligence Scale-IV (WAIS-IV) [1] incorporates significant structural and content revisions in comparison to the WAIS-III [2]. The WAIS-IV manual outlines the underlying four-factor structure of the WAIS-IV [1], where there is strong construct validity support for the four indexes, comprising: Verbal Comprehension (VC); Perceptual Reasoning (PR); Working Memory (WM); and, Processing Speed (PS). Each of these Indexes contributes to providing a composite score that represents overall general intellectual ability (i.e. Full Scale IQ). The four-factor model contributes to an overall second-order g factor, known as the Full Scale IQ, which comprises overall general intelligence.

Methods

Results

Conclusion