For groupwork to support learning it requires that students establish mutual knowledge, which is information that becomes shared among all group members. In this study, we analyzed the verbal interactions of two groups of high school students working on a color vision activity. Students within a group each wore different color-filtering goggles, and compared their individual perceptions to identify various colors they viewed together. Because the color-filtering goggles gave each student different information related to the task, sharing knowledge was necessary for successful color recognition. Our analysis was guided by the questions, how did students establish mutual knowledge through their talk? And, what types of knowledge were shared through these processes? We found that students were more inclined to explain—including providing warrants for their claims—when they used discussion moves such as asking each other questions, reacting to each other's statements, and incorporating multiple perspectives. Practical interventions designed to teach students to work productively in groups should attend to expectations around the content of students' talk in addition to the range of talk moves that students can use to contribute to a discussion.

为了让小组合作支持学习，学生需要建立相互知识，即所有小组成员之间共享的信息。在这项研究中，我们分析了两组从事色觉活动的高中生的言语互动。一组中的学生每个人都戴着不同的滤色眼镜，并比较他们各自的感知，以识别他们一起看到的各种颜色。由于滤色镜为每个学生提供了与任务相关的不同信息，因此共享知识对于成功进行颜色识别是必要的。我们的分析以以下问题为指导：学生如何通过谈话建立相互的知识？并且，通过这些过程共享了哪些类型的知识？我们发现，当学生使用诸如互相提问、对彼此的陈述做出反应以及纳入多种观点等讨论动作时，他们更倾向于解释，包括为自己的主张提供依据。旨在教会学生在小组中高效工作的实际干预措施除了学生可以用来促进讨论的谈话动作范围之外，还应该关注对学生谈话内容的期望。