ABSTRACT

 Continuous Assessment (CA) is a cornerstone of student evaluation in Nigerian secondary schools. However, discrepancies in CA practices raise concerns about fairness and standard maintenance.This study investigates the robustness of test score equating methods (linear equating, concurrent calibration,and separate calibration) in comparing and maintaining standards in CA measures across two South-South states in Nigeria. This study's scope was limited to South- South geopolitical zones to provides a starting point for understanding these challenges, but including more regions in further studies would make the findings applicable nationwide. The population of the study comprised of all Senior Secondary Three (SSIII) student's of 2021/2022 academic session in both states, and a sample of 1,605 students was drawn through multi-stage sampling procedure from the population. Parallel Mathematics Achievement Tests (MAT) with reliability of 0.84 and 0.88 respectively, were administered alongside existing mathematics CA scores. Three research questions and three hypotheses guided the study. Descriptive statistics was used in answering the research questions, while hypotheses were tested using independent t-test and Pearson product moment correlation coefficient. Scores were analyzed using linear equating, concurrent calibration, and separate calibration methods, leveraging SPSS and BILOG-MG. The findings revealed no significant differences in ability estimates using concurrent calibration but significant differences in linear equating, with Akwa lbom outperforming Rivers (mean difference= 4.42). A moderate positive correlation (r = 0.42-0.43) between CA and Mathematics Achievement Test (MAT) scores was also observed.The study underscores the effectiveness of linear equating for standard maintenance, recommending its integration alongside standardized CA practices.To enhance the generalizability of findings, future studies should include more regions. Furthermore, contextualizing global equating practices to Nigeria's educational challenges and exploring advanced equating methods like equipercentile equating are recommended.