The document summarizes a study of five successful urban charter schools in Massachusetts. The schools were found to share key factors for their success, including a clear mission and strong institutional culture, purposefully selecting teachers and leaders who fit the school culture, and organizational structures and systems that support student learning. While the schools emphasized academic rigor and preparation for college, classroom instruction varied and sometimes focused more on memorization and lower-level thinking. The schools were very successful on state standardized tests but students' performance declined on the SAT, raising questions about preparing students for long-term success.