中文摘要：

远程协作学习的方式不仅改变了学生的学习环境，教师的角色、态度和职责也发生了相应的改变。通过内容分析法和关键事例访谈法，对一门在线课程的协作学习异步交互过程进行研究，发现教师可以承担多种角色，如制定有意义的任务，提供技术支持、专业内容和资源等，同时教师参与的积极性、时间性、适度性与协作学习效果有显著关系。

英文摘要：

Collaborative learning in distance not only changes the learning environment, but also makes a distinct difference towards teachers＇ role, attitude and responsibility. By using content analysis and Critical Incident Recall, we conduct a research on the asynchronous collaboration interaction of a distance course. The results show that the teacher is taking diverse roles in distance collaborative learning, such as planning meaningful tasks, providing technical support, facilitating participation and preparing resources for extended learning. Meanwhile, the participation, the time of engagement, the appropriate encourage of teachers have significant correlation with students＇ performance.