Historical Development of Lesson Study in Japan
Authors: Kusanagi Kanako N. 
Published: April 2021

Lesson study (jyugyo kenkyu) is an approach to professional development that originated in Japan 150 years ago. It was first introduced to the United States in the late 1990s and is now widely practiced in over 50 countries. Lesson study is often perceived as an effective form of professional development aiming to improve mathematics and science instruction, motivated by the high performances of Japanese students as evaluated in the Programme for International Student Assessment (PISA) and Trends in International Mathematics and Science Study (TIMSS). However, lesson study is more than a model for professional development. Lesson study has developed dynamically over time, accommodating educational contexts and the needs of practitioners, policymakers, and researchers. Nowadays, lesson study is used as an approach to lesson analysis, curriculum development, practice-oriented research, demonstration lessons, and various forms and levels of professional development. Lesson study continues to be practiced in the early 21st century as the practice is socially constructed and context-dependent; thus, lesson study is flexible in adapting to the local system.

This flexibility and adaptability make it difficult to grasp the comprehensive picture of lesson study. Understanding the unique Japanese educational contexts that have supported lesson study is essential for foreign practitioners and researchers of lesson study as the lack of the necessary supporting conditions often poses challenges for implementing lesson study abroad. Lesson study continues to exist in the early 21st century as it has been facilitated by sociocultural norms in a Japanese educational context and has built upon the professional traditions of Japanese teachers. The focus is on discussing the sociocultural contexts that have supported the dynamic development of lesson study since the late 19th century. For this purpose, “sociocultural” refers to the theoretical space of social relations and cultural practice (Dowling, 2009). For example, a collaborative school culture is not a fixed state or end-product but negotiated through the social relations of the school system that regulates the daily responsibilities, actions, and interactions among managers, teachers, and students around the shared goals.

Lesson study has developed under the influence of various factors, including educational theories, approaches, and ideologies, both domestically and abroad. Lesson study is supported by a holistic approach in terms of many aspects such as student learning, teacher-initiated inquiry centered on student learning, the culture of collaboration in professional development, collaboration between teachers and researchers, personal, contextual, and narrative reflection on teaching experience, and flexibility in the learning system that works to address the needs of the educational issues of the time. Nonetheless, contesting forces have contributed to the diversification of lesson study: (a) policymakers’ efforts to standardize lessons and bottom-up initiatives of teachers to experiment with practice; (b) top-down efforts to institutionalize professional development and bottom-up efforts on the part of teachers to work together to realize their educational ideals; and (c) scientific investigation by researchers and narrative, descriptive and subjective reflections on practice by teachers.