As introductory physics courses increasingly focus on student engagement, the use of Learning Assistants (LAs) has increased. LAs and other instructors need to have sufficient PCK to effectively guide student learning. Our goal was to research LAs observed PCK in the classroom and to develop a set of questions to assess LAs’ PCK. Our research question was: Is it possible to assess LAs’ observed PCK with open-ended written questions? We video-recorded student-LA interactions in the introductory physics classrooms, developed rubrics to describe the interactions between LAs and students, and developed free-response questions based on the authentic interactions from the videos. Our results are (1) a rubric to assess LAs PCK in video recordings or free response written assessments and (2) a set of open-ended written questions that assess LAs PCK. The LAs were dominant in one or two categories in both the written and video coding, making it possible to draw conclusions about their PCK. We answered our research question by demonstrating the development and validation of a set of questions to assess LA’s PCK. Our rubric can be used to analyze both videos and written questions by supervisors who are interested in assessing their LAs’ PCK.

随着物理入门课程越来越注重学生的参与度，学习助手 （LA） 的使用有所增加。LA 和其他教师需要有足够的 PCK 来有效地指导学生的学习。我们的目标是研究 LA 在课堂上观察到的 PCK，并开发一组问题来评估 LA 的 PCK。我们的研究问题是：是否有可能用开放式书面问题来评估 LA 观察到的 PCK？我们在物理入门课堂上录制了学生与 LA 的互动视频，制定了描述 LA 和学生之间互动的评分标准，并根据视频中的真实互动开发了自由回答问题。我们的结果是 （1） 在视频录制或自由回答书面评估中评估 LA PCK 的评分标准，以及 （2） 一组评估 LA PCK 的开放式书面问题。LA 在书面和视频编码的一两个类别中都占主导地位，因此可以得出关于他们的 PCK 的结论。我们通过演示一组问题的开发和验证来评估 LA 的 PCK 来回答我们的研究问题。我们的评分量规可用于分析有兴趣评估其 LA 的 PCK 的主管的视频和书面问题。