Instructional feedback has the power to enhance learning. However, learners do not always feel satisfied with their feedback experience. Simultaneously, little attention has been paid on investigating how feedback is implemented in online competency-based learning (CBL). CBL is an approach under which learning activities are organized in a non-linear manner to help learners achieve pre-defined competencies. This study applied a multiple case study method, and 17,266 pieces of the coded feedback text, given by instructors for three learning tasks from a blended undergraduate course, were analyzed. The results showed that instructors implemented 11 types of feedback. Feedback that was used to give praise was less effective, but was frequently used. Regulative feedback and emotional feedback can be very effective, but they were actually rarely used. Feedback for diagnosis, suggesting improvements, and praise was frequently and consistently used across tasks with different complexity. In contrast, feedback used for complementary teaching and time management, as well as emotional feedback were rarely used. Based on the obtained findings, the potential causes and suggestions for improving feedback implementation were discussed.

教学反馈具有增强学习的能力。但是，学习者并不总是对他们的反馈经验感到满意。同时，对于如何在基于在线能力的学习（CBL）中实施反馈进行调查方面，人们很少关注。CBL是一种以非线性方式组织学习活动以帮助学习者实现预定能力的方法。这项研究采用了多案例研究的方法，并分析了由教师针对混合型本科课程的三个学习任务给出的17266条编码反馈文本。结果表明，教师实施了11种反馈。用于赞美的反馈效果较差，但经常被使用。调节性反馈和情绪反馈可能非常有效，但实际上很少使用。诊断反馈，改进建议和表扬经常在不同复杂性的任务中持续使用。相反，很少用于辅助教学和时间管理的反馈以及情感反馈。基于获得的发现，讨论了改善反馈实施的潜在原因和建议。