The Impact of Baseline Scores in Performance Assessment on the Determination of Minimum Achievement Levels in the High School Credit System

This study examines the impact of baseline scores in performance assessment on the proportion of students failing to meet the minimum achievement level under the high school credit system. In Korean high schools, baseline scores in performance assessment are generally set within the range of 10% to 40% of the total score. Meanwhile, with the introduction of credit completion requirements under the high school credit system starting in 2025, students whose academic achievement falls below 40% in each subject must be identified as underachieving and provided with supplementary instruction to ensure minimum achievement levels. In this context, concerns have been raised that assigning baseline scores of up to 40% of the total performance assessment score may contradict the intended purpose of the policy. To address this issue, this study investigates the extent to which baseline scores influence the proportion of students not meeting the minimum achievement level. Based on the findings, it further explores an appropriate range of baseline scores that does not excessively reduce the proportion of underachieving students. Simulation data were generated to reflect various school contexts with different score distributions and weighting ratios between written and performance assessments. By adjusting baseline scores from 0% to 40%, changes in the proportion of underachieving students were analyzed. The results indicate that, under a typical academic distribution observed in general high schools (with an average score of 60), assigning baseline scores exceeding 30% of the total performance assessment score can reduce the proportion of underachieving students to nearly zero. Therefore, to prevent an excessive reduction in the proportion of students failing to meet the minimum achievement level, it is recommended that baseline scores in performance assessment should not exceed 20% of the total score across subjects.