Engaging students in mathematical argumentation supports language development and conceptual understanding because students use verbal and written language in coordination with mathematical representations to notice patterns, make claims, and create and revise explanations. This study adds to the limited research base on how teachers learn to facilitate discussions specifically aimed to develop students’ capacities to engage in argumentation. We analyze teachers’ sensemaking about supporting argumentation in the classroom through their participation in an adaptive professional development (PD) design. The PD was embedded in two elementary schools with upper grade teachers which enabled them to engage in iterative cycles of investigation and enactment within their own classrooms. Through collaborative lesson design and inquiry into students’ experiences, teachers attended to the language students produced as they tried to formulate conjectures and produce explanations and the classroom participation structures that supported them. Our results suggest shifts in how teachers understood their role. Both cases speak to the complexities teachers face as they try to realize the recommendations for enhancing language learning and provide insight into what “rich” discourse means.

让学生参与数学辩论支持语言发展和概念理解，因为学生使用口头和书面语言并结合数学表示法来注意模式，提出主张以及创建和修改解释。这项研究增加了有限的研究基础，即教师如何学习以促进专门旨在提高学生参与辩论的能力的讨论。我们通过教师参与自适应专业发展（PD）设计来分析教师在课堂上支持辩论的意义。该效绩数据嵌入了两所小学，其中有高年级老师，使他们能够在自己的教室中进行反复的调查和制定。通过协作式课程设计和对学生体验的探究，教师参加了语言学生的学习，他们试图提出猜想并提出解释，并为他们提供了课堂参与结构。我们的结果表明，教师对角色的理解方式发生了变化。这两种情况都说明了教师在尝试实现有关增强语言学习的建议并提供对“丰富”话语意味着什么的见解时面临的复杂性。