All work to improve the quality of profes- sional development must begin with one simple assumption: Teaching is an incredibly complex profession that draws on a wide set of intellectual and emotional skills. Even the best teachers need to continue to learn and improve their practice, and many are willing to do so. The bottom line is that all teachers — all educators — grow from professional learning experiences that sharpen their practice. However, the teaching profession in America is at a crossroads. Designed more than a century ago, in many ways teach- ing remains stuck in an outmoded and inadequate system of preparation and improvement. States, districts, and the federal government spend $25 billion annually on support services to develop teachers and leaders (U.S. Census Bureau,