As the 2015 revised national curriculum is being implementing in Korea, a teacher’s assessment competency has become a point of focus for the potential enhancement of students’ self-directed learning. Relevantly, a teacher’s competency in student assessment is correlated to his/her individual feedback practices. Although students’ self-directed learning affects academic performance and may vary based on their teachers’ assessment competency, few studies have investigated the effect of a teacher’s assessment competency, specially feedback practices, on student outcomes. Therefore, this study aims to empirically investigate the differential effect of a teacher’s assessment competency, particularly focusing on feedback practices (i.e., formative assessment feedback, homework feedback), on Korean students’ individual learning times and math achievements. For the analysis, a 3-level hierarchical linear modeling (HLM) is employed using data of middle school students (N = 2942) and math teachers (N = 426) in 207 middle schools of the Gyeonggi Education Panel Study (GEPS). The study revealed that a teacher’s formative assessment feedback has a positive differential effect on math performance when controlling for student-, teacher-, and school-level covariates. In addition, the effect of individual learning time on math achievement was significantly dependent on teachers’ homework feedback. The study provides newfound empirical evidence that teacher feedback plays a pivotal role in promoting a student’s self-directed learning and academic achievement. Based on these findings, the implications of improving a teacher’s assessment competency are discussed.

随着韩国正在实施2015年修订的国家课程，教师的评估能力已成为潜在增强学生自我导向学习的重点。相应地，教师在学生评估中的能力与他/她的个人反馈做法相关。尽管学生的自主学习会影响学习成绩，并可能因教师的评估能力而异，但很少有研究调查教师的评估能力（特别是反馈做法）对学生成绩的影响。因此，本研究旨在通过经验研究教师评估能力的不同影响，特别是关注反馈实践（即形成性评估反馈，家庭作业反馈），韩国学生的个人学习时间和数学成绩。为了进行分析，我们使用了三级分层线性建模（HLM），其中使用了中学生的数据（ 京畿道教育专家小组研究（GEPS）的207所中学的 数学老师（N = 2942）和数学老师（N = 426）。该研究表明，在控制学生，教师和学校水平的协变量时，教师的形成性评估反馈对数学成绩有积极的影响。此外，个人学习时间对数学成绩的影响很大程度上取决于教师的家庭作业反馈。这项研究提供了新的经验证据，表明教师的反馈在促进学生的自主学习和学习成绩方面起着关键作用。基于这些发现，讨论了提高教师评估能力的意义。