國中讀前段班有差嗎？能力分班對學習成就影響的反事實分析 Does It Make a Difference in Being Assigned to High-Ability Groups in Junior High? A Counterfactual Analysis of the Effects of Ability Grouping on Students’ Academic Achievement in Taiwan

本研究以「臺灣教育長期追蹤資料庫」國中樣本兩波資料，分析八、九年級讀前段班對九年級時學習成就的影響。本研究以就讀無能力分班措施學校且自認從無分班經驗者為對照組，分別與學校無能力分班、學校只有部分年級有分班，以及學校各年級均有分班措施等三類型學校內，自認於八及九年級與只有九年級讀前段班者相比較，以評估讀前段班是否影響九年級的學習成就。分析模型包括 多層次線性、單層次傾向分數配對分析，以及結合單層次傾向分數配對與多層次交叉分類隨機效應模型等。研究發現，以單層次傾向分數分析或此方法結合多層次交叉分類隨機效應模型的結果觀之，只有就讀於部分年級有分班學校，且於八及九年級讀前段班或只於九年級讀前段班會對正面影響九年級學習成就。 The present research assesses the causal effects of being assigned to high-ability groups in junior high according to 9th graders’ academic achievement in Taiwan. Using data gathered by the Taiwan Education Panel Survey in 2001 and 2003, the sample is divided into three school types: schools with no ability grouping, schools grouping students only at certain grades, and schools grouping students in all grades. Within each school type, this research focuses on estimating the average treatment effect (ATE) by comparing separately the achievement of 9th graders who have self-identified to high-ability groups in both 8th and 9th grade, or in 9th grade only, to those having no tracking experience and enrolled in schools without ability grouping. The research uses multilevel linear modeling, single-level propensity score matching (PSM), and the combination of single-level PSM and cross-classified random effects model (CCREM) to estimate the ATE of being assigned to high-ability groups. According to the analysis of the model combining PSM and CCREM, the research finds that only students assigned to high-ability groups at schools which group students at certain grades have positive impacts on their 9th grade achievement