Teacher Learning with Lesson StudyA Murata, Stanford University School of Education, Stanford, CA, USAã 2010 Elsevier Ltd. All rights reserved.

Introduction Lesson study is a collaboration-based teacher professional development approach that originated in Japan (Fernandez and Yoshida, 2004; Lewis and Tsuchida, 1998; Stigler and Hiebert, 1999). When it was first introduced in the United States in the late 1990s, it quickly gathered the attention of the US educators as it was thought to be an adoptable and effective innovation (Choksi and Fernandez, 2004; Lesson Study Research Group, 2007; Lewis et al., 2004; National Research Council, 2002; North Regional Educational Laboratory, 2002; Richardson, 2004; Stepanek, 2001, 2003; Wilms, 2003). Lesson study incorporates effective characteristics of other professional development programs identified in prior research. It is site based, practice oriented, focused on student learning, collaboration based, and research oriented (Bell and Gilbert, 2004; Borko, 2004; Cochran-Smith and Lytle, 1999, 2001; Darling-Hammond, 1994; Wang and O’Dell, 2002; Little, 2001; Hawley and Valli, 1999; Wilson and Berne, 1999). Lesson study was also one of the foci for the International Congress on Mathematics Education (ICME) Ninth Conference in 2002 and has spread in many other countries (Fujita et al., 2004; Lo, 2003; National College for School Leadership, 2004; Shimizu et al., 2005). Despite the rapid rate of adoption, this form of professional development is still new in countries other than Japan, and thus schools and teachers in these countries are still at the early stage of adopting the innovation to their existing systems. There is an emerging body of lesson study literature, but we do not yet have a coherent and shared understanding and model of teacher learning with lesson study. The purpose of this article is to give an overview of lesson study with its structure (and variation), its history, and emerging lesson study research literature, in order to explicate teacher learning models in lesson study as well as to identify future research agenda with lesson study.