Makoto Yoshida
This summary of lesson study provides a concise rationale for the practice. A basic description of the process is followed by tips for how to implement lesson study most effectively and why a written record of the work is so important.
Confucius said that seeing something once is more important than discussing it 100 times. Lesson study provides a concrete image of good teaching practices in the classroom.
It also creates classroom-based research on instruction and learning. Lesson study gives teachers the opportunity to investigate their instructional materials and classroom teaching practices by examining students' ways of thinking, understanding, and learning.
Lesson study can then stimulate new ideas for improving instructional materials, teaching, and student learning.
Lesson study can provide focused, coherent, and consistent education for students, in part because of its collaborative nature. It also helps to develop a common understanding of curriculum, instruction, and educational goals, while also helping teachers to better understand their own students.
Lesson study helps to make teachers into lifelong learners. It is especially important to think of lesson study as a professional development activity, not as teacher training and lesson development. It creates opportunities for teachers to think deeply about instruction, learning, curriculum, and education. Teachers who do lesson study become independent thinkers and problem solvers and may find joy in learning mathematics content, teaching, and learning throughout their careers.
Finally, the primary purpose of lesson study is not to compile a library full of good lesson plans. This is useful, but it should be a byproduct instead of the main goal of lesson study. A library of good lesson plans may not be effective in the classroom if teachers are not educated as deep thinkers who can understand the rationale and objectives of those lessons.
The central process of lesson study (see figure) involves a lesson planning group that develops a lesson plan. One of the members of the group then teaches a research lesson to a class of students while research lesson participants observe and collect data on student thinking and learning. Observers can include teachers from other schools in the same district as well as teachers from other districts. Everyone takes part in the follow-up debriefing session. The discussion group can help the lesson planning group revise the lesson plan while other participants examine the lesson in the context of their own classrooms. The revised lesson plan is then used to teach another class of students. The ultimate purpose it to yield new ideas about teaching and learning for everyone involved.

It is important to understand that students are at the heart of the process of lesson study. Once teachers establish a lesson study goal, they need to think about goals of the unit and think of the lesson they are working on as a research lesson. Having clear goals helps teachers be clear about what they are studying in the classroom with their students and helps them to determine if the lesson achieved the goals. Careful investigation of instructional materials also helps teachers to determine the clear goal.
Knowing more about the content, scope, and sequence of curriculum helps teachers to be clear about where they are going with the lesson they are preparing and what outcome they are looking for from the students. During the research lesson, participants should observe carefully in order to collect their data. Observers should also record what students are thinking and how they make sense of what they are learning. Teachers reflecting on the research lesson should keep in mind the evidence observers collected during the lesson as well as the lesson goal, lesson study goals, and unit goals.
Effective lesson study can have an impact on teachers' daily practice because they learn ways to think about planning lessons and to look at students' thinking and learning. It can also create educational strategies that are focused, coherent, and consistent, as teachers work in a collaborative setting and study their instructional materials, exchanging ideas for teaching and learning in the classroom. Effective lesson study also influences teachers' attitudes about being professionals; through the process they learn to become reflective practitioners, autonomous independent problem solvers, and lifelong learners-skills and attitudes that teachers often expect from their students. Teachers often discover new joy for the subject they are teaching and are inspired to continue to study their materials. Lastly, effective lesson study has long-term impact on students' learning, since well-prepared classroom practitioners (who have a strong understanding of subject content knowledge and pedagogy) can produce better results.
Lesson study can help teachers to become lifelong learners, independent thinkers, and problem solvers, but it also helps them to enjoy investigating the instructional materials and learning about and from their students. These can all be motivations for sustaining lesson study practice over time. As Alice Gill said at the 2002 Lesson Study Conference, "When lesson study is done well, the learning itself is the most powerful support to sustain involvement and attract new participants. It will glow in the teachers and show in the students."
Groups may want to celebrate the conclusion of a lesson study cycle with a party, but the learning should not end there. Writing reports-both research lesson reports and year-end lesson study reportsis an important part of the lesson study process. Teachers should take some time to reflect and summarize their learning in order to produce a record of the process. This also creates resources for individuals, the lesson study group, and people outside of the group to use in future research and learning.
Raw data (in the form of videotaped lessons, protocol, data collected during observation, example of students' works, minutes of discussions, etc.) may not be adequate to help others easily identify what teachers learned from lesson study. Teachers are less likely to revisit these raw materials if they are not organized in some manner.
It is always very difficult to compile a report after completing research lessons. Teachers need to take notes for their own learning while engaged in lesson study. Notes taken on discussion during the planning process, lesson observation, and discussion during debriefing of the lesson can serve as resources for producing a report. Even if there is a designated note-taker at meetings, all participants should take notes of the discussion.
A summary of learning should reflect on the relationship between the goals and the research lesson: "What aspect of the goal was achieved? What was effective to achieve the goal?" The report can also identify any issues that the group needs to explore in the future.
This paper was first published online in July 2004.