Most readers of the Kappan will know that lesson study is a Japanese approach to teacher professional development that has recently become popular in the U.S. Indeed, lesson study activity has been spreading rapidly for several years and continues to proliferate today. However, to date, most of the discussion and research about U.S.-based lesson…

Recently, there has been a rapid proliferation of lesson study groups in the United States. Since deep knowledge about lesson study is rare in the U.S., it is likely that some of these groups have an incomplete understanding of this Japanese practice. Some may focus on structural aspects of the process of lesson study or may mimic its superficial…