When charter schools first entered the landscape, the debate was contentious, with both advocates and critics using strong rhetoric. Advocates often sold charter schools as a silver bullet solution for not only the students who attend these schools, but the broader traditional public school system as well. Similarly, critics painted charter schools as an apocalyptic threat to public schools. To inform this debate, research has evolved over time, with much of the first generation (through about 2005) of research studies focusing on the effect charter schools have on test scores almost exclusively using non-experimental designs. The second generation of studies more frequently used experimental designs and broadened the scope of outcomes beyond test scores. Furthermore, the second generation of studies has also included studies seeking to explain the variance in performance. In this survey of the research, we summarize the findings across both generations of studies, but we put a greater emphasis on the second generation than prior literature reviews. This includes an examination of indirect effects, examination of explanation of charter effectiveness, and the recent use of charter schools as a mechanism of turning around low-performing schools.