EVALUATING THE LONGITUDINAL IMPACT OF MATHEMATICS CURRICULUM REFORMS ON STUDENTS’ ACHIEVEMENT IN NIGERIA: A MULTI-COHORT ANALYSIS

Mathematics curriculum reforms in Nigeria have been implemented over the past decades to improve students’ academic achievement, problem-solving abilities, and readiness for scientific and technological advancement. This study examines the longitudinal impact of these reforms on student performance using a multi-cohort analysis, with a focus on content structure, pedagogical approaches, and assessment strategies. Data were collected from public examination records, school-based assessments, teacher surveys, and curriculum documents across three successive cohorts of secondary school students. The findings indicate that restructured content with spiral sequencing and real-life applications, learner-centred pedagogies such as problem-based and inquiry-based learning, and continuous and formative assessment strategies significantly enhanced students’ mathematics achievement across cohorts. However, the magnitude of these effects varied depending on the fidelity of implementation, teacher proficiency, and available instructional resources. The study underscores that curriculum reform alone does not guarantee improved learning outcomes; rather, sustained achievement gains depend on coherent alignment of content, pedagogy, and assessment within supportive teaching and learning environments. Recommendations include ongoing teacher professional development, curriculum refinement, and broader adoption of formative assessment practices to optimize the long-term impact of mathematics curriculum reforms in Nigeria.