The successful use of lesson plans as the primary vehicle for storing and sharing teachers’ instructional knowledge in Japan has given impetus to calls by US researchers for the development of a system for sharing teachers’ knowledge through instructional products to improve teachers’ capacity to implement high-quality instruction and to build a knowledge base for instruction. These products would be created by, and for, teachers to use in guiding instruction, thus building and sharing teachers’ instructional knowledge. In this study, we try to characterize one aspect of teacher knowledge that is central in building a knowledge base for instruction, knowledge of student mathematical thinking. We analyze ten written instructional products from the USA and Japan to better understand what knowledge of student mathematical thinking can be shared in such products. We also look at how knowledge of student mathematical thinking is used to guide and justify instructional decisions. One key finding is that the knowledge of student mathematical thinking shared in the top written instructional products is specific to a task or mathematical topic, varied with descriptions of multiple solutions or ways of reasoning, and sufficiently detailed to make the knowledge usable for teachers.

在日本成功地使用课程计划作为存储和共享教师教学知识的主要手段，这激励了美国研究人员呼吁开发一种通过教学产品共享教师知识的系统，以提高教师实施高水平教学的能力。优质的教学，并建立知识库。这些产品将由教师创建，并供教师用于指导教学，从而建立和共享教师的教学知识。在本研究中，我们试图刻画教师知识的一个方面，这是建立教学知识基础，学生数学思维知识的核心。我们分析了来自美国和日本的十种书面教学产品，以更好地理解可以在这些产品中共享哪些学生数学思维的知识。我们还将研究如何将学生数学思维的知识用于指导和证明教学决策的合理性。一个主要发现是，在顶级书面教学产品中共享的学生数学思维知识是特定于任务或数学主题，随对多种解决方案或推理方式的描述而变化，并且足够详细以使知识对教师可用。