DIFFERENTIAL ITEM FUNCTIONING ANALYSIS OF 2022 AND 2023 ALGEBRA AND ELEMENTARY TRIGONOMETRY EXAMINATIONS AT FEDERAL POLYTECHNIC DAURA, KATSINA STATE, NIGERIA.

Abstract

This study examined Differential Item Functioning (DIF) in the Algebra and Elementary Trigonometry examinations administered in 2022 and 2023 at Federal Polytechnic Daura, Katsina State, Nigeria. The investigation was motivated by consistently poor student performance in these subjects, characterized by high failure rates and low grades. Using the Mantel–Haenszel procedure and logistic regression, item responses from 110 students were analyzed to identify DIF across gender and socio-economic groups. The results indicated that several items exhibited significant DIF, favoring male students or those from higher socio-economic backgrounds. These findings suggest the influence of construct-irrelevant factors on performance. Recommendations include revising biased items, enhancing instructional methods, and strengthening academic support to ensure equitable assessment practices.