For several historical and cultural reasons, the United States has long pursued a strategy of improving teaching by improving teachers. The rarely questioned logic underlying this choice says that by improving the right characteristics of teachers, they will teach more effectively. The authors expose the assumptions on which this logic is built, propose an alternative approach to improving teaching that engages teachers (and researchers) directly in the work of improving teaching, present some indirect evidence to support this approach, and examine the cultural traditions and beliefs that have kept the conventional approach in place for so long. (Contains 2 notes.)