Examining the Model-Fit of Mathematics Basic Education Certificate Examination Items in Plateau Northern Zone, Nigeria.

This study examined the model-fit of mathematics items in the Basic Education Certificate Examination (BECE) in Plateau Northern Zone, Nigeria. The quality of the examination items was assessed in terms of model-fit using Item Response Theory (IRT) approaches. A descriptive survey research design, specifically a cross-sectional survey design, was adopted. The population comprised 27,869 and 29,773 upper basic students’ Mathematics BECE scripts for the years 2023 and 2024, respectively, drawn from 806 schools across six Local Government Areas in the zone. The sample was determined using 5% of the population of students scripts that wrote the Mathematics BECE for year 2023 and 2024. Using 5% of the school population, 40 schools were sampled 5 public schools (4 public urban and 1 public rural) and 35 private schools (32 private urban and 3 private rural). All the students’ scripts in the 40 selected schools who sat for the Mathematics BECE in the year 2023 and 2024 were used for the study. These give 1,393 students’ scripts in the year 2023. In 2024 the students’ scripts were 1,487.The sample size satisfied the minimum requirement (N ≥ 1000) for stable parameter estimation under the three-parameter logistic model (3PLM). Data were obtained from the Mathematics BECE question papers and students’ scripts for both years. Model fit of the examination items was determined. The findings revealed that the model fit for both 2023 and 2024 adequately fit the model. The study recommends the adoption of the IRT framework in BECE item analysis to enhance test quality and enable accurate placement of candidates based on their ability levels.