Leaders and funders of the charter school movement are working hard to identify the most promising charter schools, model new charter schools after existing schools with the highest performance, and dramatically increase the numbers of high-performing charter schools, which they call “bringing charter schools to scale.” Author Robin Lake, executive director of NCSRP and associate director of CRPE, identifies philosophical differences within the charter community itself about how to proceed and reviews the challenges of identifying and scaling up high-performing charter schools.