Assessing Cognitive Abilities Using the WAIS-IV: An Item Response Theory Approach

Area of Science:

• Psychometrics
• Cognitive Psychology
• Cross-cultural Psychology

Background:

• The Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) is a widely used intelligence test adapted globally.
• Examining the psychometric properties of culturally adapted intelligence scales is crucial for accurate assessment.

Purpose of the Study:

• To evaluate the item and scale properties of the Egyptian adaptation of the WAIS-IV.
• To investigate the psychometric performance of the Egyptian WAIS-IV using Item Response Theory (IRT) models.

Main Methods:

• Utilized IRT models (dichotomous and polytomous) to analyze item and subtest properties.
• Conducted factor analysis to assess the unidimensionality of each subtest.
• Sample comprised 250 adults from Egypt.

Main Results:

• Factor analysis confirmed the unidimensionality of individual subtests.
• The two-parameter logistic model best fit dichotomous items, and the graded response model fit polytomous items.
• The Egyptian WAIS-IV demonstrated adequate information across cognitive levels, though some items had limited discrimination or misaligned difficulty ranks.

Conclusions:

• The Egyptian WAIS-IV is a valid tool for assessing intellectual abilities in the Egyptian population.
• Minor revisions to specific items could further improve the scale's measurement precision.