[There is] growing interest in the Japanese teacher-development strategy in which teachers work cooperatively and intensively to improve their methods. This process, known as "lesson study," allows teachers to revise and refine lessons that are then shared with others, sometimes through video and sometimes at conventions. In addition to helping novices, this system builds a publicly accessible body of knowledge about what works in the classroom.This seems so commonsensical that one wonders whether American schools really are so deficient in this regard. A Google search brings up an old Joanne Jacobs post with an excerpt from a subscriber-only Education Week piece that suggests, if I'm reading it right, that American teacher development too often focuses on "generic teaching techniques" rather than more valuable specifics—"what teachers must cover and [how] students think about that content." It goes on: "[R]esearchers also have a hunch that it’s important for teachers to engage in learning sessions collectively—maybe with other teachers from the same department or grade—so that they can meet later to reflect on what they learned." That doesn't really answer the question, but it seems to suggest they don't already do this.
The lesson-study groups focus on refining methods that improve student understanding. In doing so, the groups go step by step, laying out successful strategies for teaching specific lessons. This reflects the Japanese view that successful teaching is the product of intensive teacher development and self-scrutiny. In America, by contrast, novice teachers are often presumed competent on Day One. They have few opportunities in their careers to watch successful colleagues in action. We also tend to believe that educational change would happen overnight - if only we could find the right formula. This often leaves us prey to fads that put schools on the wrong track.