This article reports how a national panel has concluded that there's little empirical evidence to show that many of the most common practices in the teacher education field produce effective teachers. The conclusion comes from a 766-page study produced by a panel of experts from the American Educational Research Association, a Washington-based group that represents 22,000 scholars. The report comes at a time when policymakers and researchers are increasingly recognizing the critical role that teachers play in student learning. That awareness was embedded in the federal No Child Left Behind Act, which calls for schools to ensure that classrooms are staffed with "highly qualified" teachers. Yet policymakers and researchers are bitterly divided over what "highly qualified" means and how best to produce teachers who meet that standard. Experts said the AERA panel's report, which came in the thick of those debates, is notable both for the "evenhanded and critical" research analysis it attempts to undertake and the fact that it was finished at all.