课堂教学是学校教育工作的中心，课堂教学质量是衡量课程改革成效的关键指标。追求高质量的课堂教学是一线教师、课堂教学研究者的共同目标。而通过跨文化的视角对高质量课的特征进行比较分析是教学改进的有效路径。美国基础教育数学课程改革运动具有世界性影响，其高质量数学课堂教学对于我国具有较强的可借鉴性。比较分析中美高质量数学课堂教学具有重要的理论和现实意义。

本研究依托一项中美合作项目，整合高质量课堂教学实践和教师的高质量教学观两种视角，对中美两国常态高质量数学课堂的特点进行较为全面、系统的分析和比较。研究以常态课中的高质量课为研究对象，样本选取兼顾示范性、借鉴性及常态性。中国的高质量课从五个城市学区的 224 节课中选出，共 16 节;美国的高质量课从四个城市学区的 252节课中选出，共16节。同时收集了两国高质量课执教教师对高质量教学认识的访谈数据研究采用混合研究范式，主要运用比较法、课堂录像编码法、访谈法等研究方法。通过“基于文献形成初步编码一观看课堂录像修改、确定编码一实施编码”三阶段发展了由课堂结构、师生教学行为、师生互动组成的中美高质量课堂教学比较编码系统。通过类属分析，不断比较分析访谈数据，借助质性分析软件 Nvivo 和 Matlab2016 软件编程分析录像数据，同时结合反复的课堂录像观察进行比较、分析，得出以下结论:
1.中美两国数学教师对高质量教学的认识异大于同。
主要共同点有:(1)两国教师均认为高质量课堂学生积极参与。(2)两国教师都认为高质量课堂气氛活跃、融洽，学生有较强的求知欲，对所学内容表现出浓厚的兴趣，学习的主动性强。(3)两国教师均肯定精心的教学设计，认为高质量课须经过悉心设计和准备。主要差异有:(1)有效教学方式选择差异，中国教师认为高质量课堂教学方式以启发式讲解为主，学生积极参与，师生之间有良好的互动:而美国教师则认为组织学生进行课堂讨论为高质量课堂有效的教学方式。(2)教学目标表述差异。中国教师认为高质量课堂教师应顺利完成教学任务,“落实”教学目标;而美国教师则认为高质量课堂学生应明确知晓学习目标和任务。(3)课堂互动侧重差异。中国教师重视师生之间的互动，而较为忽视生生间的互动;美国教师则重视师生互动的同时，也注重生生间的互动。(4)课堂教学主体责任认识的差异。中国教师偏重强调教师在课堂教学中的责任，强调教师的主导地位:而美国教师则强调学生为学习的主要责任者，教师是课堂的组织者、引导者和合作者。(5)高质量课堂核心观测要素差异。中国教师认为教学效果和课堂气氛对课堂质量的贡献度最大;而美国教师则认为学生投入和课堂讨论对课堂质量的贡献度最大。

2.中美两国高质量数学课堂教学实践异大于同。主要共同点有:(1)注重数学任务，两国高质量课堂主要时间用于教学数学任务。(2)讲解是两国高质量课堂最常用的、最基本的教学行为之一。(3)听讲是两国高质量课堂中最主要的学习行为之一。(4)“讲解一听讲”是两国高质量课堂主要师生互动类型之一。(5)关注学生主体作用的发挥。中美高质量课堂中教师均安排有一定的教学时间供学生自主学习或者合作学习，且学生均有较多机会上台讲演。
主要差异有:(1)课堂结构差异。一是教学环节使用差异，中国高质量课堂教学环节连贯，有明确的知识主题，知识点教学是核心教学环节，学生不直接学习教学目标，相对缺少通过操作、实验学习数学的机会，教师善于运用课堂总结。而美国高质量课堂管理灵活，教师注重对教科书的使用，课堂中的多数数学任务来源于教科书，学生有机会直接学习教学目标;二是数学任务处理差异，中国课堂数学任务的使用量显著多于美国，更多的时间被分配于总结任务环节。而美国课堂分配更多的时间于解答任务环节，学生有充足的时间思考、探究;三是教学节奏与密度差异，中国课堂结构呈现出密集的特点，以“小步子”开展。而美国课堂结构呈现出稀疏的特点，以“大步子”开展。(2)教学行为差异。其一，主要教学行为差异，中国高质量课堂教学行为以提问为主，而美国高质量课堂以小组指导为主;其二，相同教学行为发生场域的差异，如中国课堂中教师巡视常发生于学生独立练习的过程中，而在美国课堂中则常发生于学生小组合作学习过程中;其三，教学媒体使用的差异，中国教师更多进行板演，美国教师则更多依赖新型媒体;其四，主要学习行为的差异，回答问题是中国课堂中最主要的学习行为，而小组交流是美国课堂中最主要的学习行为;其五，相同学习行为机会获得差异，中国课堂学生获得记笔记的机会高于美国课堂，而美国课堂学生提出问题的机会高于中国课堂，等。(3)课堂互动差异。第一,互动主体差异，中国课堂以公共性的师班互动和师个互动为主，缺乏非公共性的师组互动和生生互动。而美国课堂以非公共性的师组互动和生生互动，以及公共性但非集体性的师个互动为主;第二，主要师生互动类型差异,“讲解一听讲”是中国课堂中发生频率最高的师生互动类型，而“小组指导一小组交流”是美国课堂师生互动的主要类型，中国课堂中该类型的师生互动发生密度低。中国课堂中“提问一全体回答问题”型互动的发生密度高于美国:美国课堂中“提问一个别回答问题”型互动的发生密度高于中国。3.中美两国数学教师对高质量课堂教学的认识与其教学实践之间具有一致性。中美高质量课堂教学实践的差异与两国教师高质量课堂教学观的差异基本吻合。两国教师对高质量课堂教学的认识很好地体现到其教学实践当中。
中美两国教师无论是对高质量课堂教学的认识还是高质量教学实践都有一定的共性，但是更多的却是差异性。同样是高质量课堂教学，但是在各自的文化环境内有不同的表征和特点。不存在统一的、放之四海而皆准的好的教学方式，应合理地、有选择性地吸收国外的教学经验。

Instruction is the center of school education, and the instruction quality is the key index to measure the result of curriculum reform. Thus high-quality instruction is the main target of teachers and instruction researchers. And comparing the characteristics of high-quality instruction from a comparative perspective is an effective way for instruction improvement. The movement of mathematics curriculum reform of basic education in the United States has a worldwide influence, therefore the high-quality mathematics instruction of America is strongly referential to China.

This study is based on a China-America cooperated project, which integrally and systematically analyzed the characteristics of high-quality mathematics lessons in normal lessons of China and America, from both the perspectives of practice and the idea of high-quality instruction. The research objects in the study were high-quality lessons in normal lessons, combining the thinking of exemplariness, reference and normality. The sixteen high-quality lessons of China were selected from 224 normal lessons from five urban districts, and the sixteen high-quality lessons of America were selected from 252 normal lessons from four urban districts. Meanwhile the data from the interview with the teachers of high-quality lessons of China and America was collected.

Mixed research methods were used in the study, including lesson video observation, lesson video coding, interview, etc. The coding system of comparing high-quality lessons of China and America was developed, which included lesson structure, teacher-student teaching and learning behavior, teacher-student interaction, with three steps: “primary coding based on literature—revising and confirming codes with watching lesson videos—formal coding”. Through category analysis, continuous comparative analysis of interview data, analysis of video data with Nvivo and Matlab2016, combined with the repeated lessons video observation and analysis, the main conclusions were as follows.

First of all, there are more differences than similarities in the understanding of high-quality instruction between Chinese and American teachers.

The main similarities are as the followings: (1) both Chinese teachers and American teachers believe that students participate actively in high quality instruction. (2) the teachers of both countries believe that the classroom atmosphere of high-quality instruction is active and harmonious, and the students are eager for knowledge, show strong interest in what they have learned, and have strong learning initiative. (3) the teachers of both countries believe that high-quality courses should be elaborated designed and prepared.

The main differences are as the followings: (1) The difference on selection of effective teaching mode. The Chinese teachers consider that for high-quality instruction, heuristic explanation is the main method of instruction, besides, students actively participate in instruction, and good teacher-student interaction is involved. While the American teachers consider that organizing students discussion is the effective teaching way for high-quality instruction. (2) The difference on statement of instruction target. The Chinese teachers believe that teachers should finish teaching task in high-quality instruction and realize the teaching targets. While American teachers believe that students should make sense of learning targets and tasks in high-quality instruction. (3) The difference on emphasis of interaction. The Chinese teachers emphasize more on the teacher-student interaction, but neglect student-student interaction. While American teachers emphasize on teacher-student interaction, as well as student-student interaction. (4) The difference on the understanding of who is the person in charge in classroom. Chinese teachers emphasis on the responsibility and leading position of teachers in the classroom. While American teachers stress that student is the main person who charges of learning, and teacher is the organizer, guide and cooperator. (5) The difference of core observation elements in high-quality instruction. Chinese teachers believe that teaching effect and classroom atmosphere contribute the most to the quality of the instruction, while American teachers believe that students' input and classroom discussion contribute the most to the quality of the instruction.

Secondly, there are more differences than similarities in the practice of high-quality instruction between Chinese and American teachers.

The main similarities are as the followings: (1) The teaching time is mainly used in teaching mathematics task in high-quality instruction of two countries. (2) Interpretation is one of the most common and basic teaching behaviors in the high quality classroom instruction. (3) Teachers in both countries schedule a certain amount of teaching time for students to learn independently or cooperatively. (4) Listening is one of the most important learning behaviors in the high quality classroom instruction. (5) Students in both countries have many opportunities to speak up on the platform. (6) “lecturing—listening” is one of the main types of teacher-student interaction.

The main differences are as the followings: (1) the differences of instruction structure. The first is the difference of classroom teaching link. Chinese case lessons are more coherent, in which teaching is not interrupted by external interference. Also there are clear subject of knowledge, knowledge teaching are the core of teaching in Chinese lessons. Students learn teaching objectives indirectly, but are lack of learning mathematics by manipulating and experiment comparatively. Chinese teachers are better in using lesson summary. However, American classroom is flexibly managed, teachers pay more attention to using textbook, most of the tasks in the classroom teaching are from textbooks, students learn teaching objectives directly; the second is the difference of mathematical task processing. The use of mathematics tasks in China is significantly more than that in America, more time is allocated to task summary. While more time is allocated to solving task in American lessons; the third are differences of teaching rhythm and density. The structure of Chinese high-quality instruction is dense, which means the lesson are conducted half step by half step, while the structure of American high-quality instruction is sparse, that means the lesson are conducted stride by stride. (2) the differences of teaching behavior. The first are the differences of the main teaching behaviors. The most important behavior of Chinese lessons is asking, while in American lessons, that is group guiding; the second are the differences of occurrence fields of the same teaching behaviors, for example, teaching inspection often occurs in the process of students' independent practice in the classroom, while that often occurs in the process of students’ group study; the third are the differences of teaching media. Chinese teachers are used to present on the blackboard, while American teachers are more dependent on the new media; the fourth are the differences of learning behaviors. Answering question is one of the most important learning behaviors in Chinese classroom, while group communication is one of the most important learning behaviors in American classroom; the fifth are the differences of opportunities of the same study behaviors. students in Chinese lessons get more chances to note, while students in American lessons get more chances to ask questions and so on. (3) the difference of teacher-student interaction. The first are the difference of Interactive subject. The main interaction types are teacher-class interaction and teacher-individual student interaction which are public, but there is also a lack of teacher-group interaction and student-student interaction, which are non-public, while non-public teacher-group interaction, student-student interaction and teacher-individual interaction that is public but not collective, are the main interaction types in the American lessons. “Group guiding- group communicating” is the main way of interaction in American lessons, which is not often frequently used in Chinese lessons; the interaction type of “askinganswering” are used more often in Chinese lessons than American lessons, and “askinganswering individually” is used more in American lessons than Chinese lessons.

Thirdly, there are consistency between the understanding and practice of high-quality instruction of China and America.

The differences of the understanding and practice of high-quality instruction of China and America are consistent. The teachers' understanding of high-quality classroom teaching is well reflected in their teaching practice. There are certain similarities in both the understanding of high-quality classroom instruction and the practice of high-quality classroom instruction, but differences are more than similarities. However, there are different performance and characteristics in their own culture context on high-quality instruction. Therefore, there is no “perfect” teaching mode which is unified and universal, teaching experiences from foreign countries should be reasonably and selectively absorbed.