論臺灣的「二一」退學制度：政治大學四種制度的量化公平性分析

On Taiwanese Universities’ Two–One Academic Dismissal Policies: A Quantitative Fairness Analysis of the Four Policies of National Chengchi University

各國大學體制中學業退學制度經常是一個作為品質把關的機制。臺灣的制度是基於個別學期的學分不及格率（semester credit fail rate, S-CFR），最常用的S-CFR是50%，俗稱「二一」，即學期學分數達二分之一不及格。雖然各校的實際退學標準存有相當大的差異，但其制度設計的核心都是基於S-CFR 的概念。本研究首先檢視美國、荷蘭與臺灣的學業退學制度的不同，指出臺灣二一制度最重要的特徵是制度的僵化，完全缺乏評估與協商機制。再者，我們透過邏輯辯證顯示，二一制度因為無視於學生的成績平均績點（grade point average, GPA），包含累計GPA（cumulative GPA, C-GPA）與學期GPA（semester GPA, S-GPA），以及累計學分通過率（cumulative credit pass rate, C-CPR），因此極易導致偏頗不公的結果，使得整體成績明顯相對較好的學生反而遭到退學。我們並且透過量化分析，觀察國立政治大學在11 年期間四種制度下的學生資料（N ＝ 22,703），驗證了二一制度所導致的不公平現象。本研究顯示現行制度應被重新檢視。

Academic dismissal policies are used by universities worldwide for quality control purposes. Taiwanese universities base their policies solely on the credit fail rate (CFR) of individual semesters (S-CFR). The most common S-CFR is 50% and is called er-yi (two-one), which indicates half or more of the course credits of a semester were failed. Though actual policies vary among universities, their core designs generally rely on the concept of S-CFR. The present study first compares the dismissal policies among universities in the United States, the Netherlands, and Taiwan to demonstrate how the two–one design lacks consultation and review processes. We then argue that the disregard for cumulative grade point average, semester grade point average, and cumulative credit pass rate may lead to bias because it may lead to students with better overall academic performance being dismissed. We further validate the argument by conducting a quantitative analysis of data on the academic performance of students (N=22,703) from National Chengchi University over 11 years under four different policies. Our findings strongly indicate that the core design common in such policies, i.e., the S-CFR, should be reconsidered.