Abstract
This study examined differential item functioning (DIF) in the 2023 English Language Multiple-choice Mock Examination in Gombe State, Nigeria. Ex-Post Facto research design was adopted for the study. The study population comprised 25,173 candidates who sat for the 2023 English Language Mock Examination in public senior secondary schools in Gombe State. A sample size of 756 was selected
from 16 public senior secondary schools using multi-stage sampling procedure. Socio-Demographic Inventory (SDI) was used to collect students' demographic details and English Language Paper I Multiple-Choice Test administered by the Gombe State Ministry of Education in the 2023 MOCK SSCE was adopted as instruments for the study. The study employed binary logistic regression analysis to
detect DIF. The results revealed that many items exhibited DIF across gender, and school type. The findings highlight the importance of examining DIF in educational tests to ensure fairness and validity. The study recommends that test developers should regularly examine DIF in educational tests and review or replace items exhibiting DIF to prevent bias against certain groups of students.