Since 1997 when Pennsylvania first authorized the establishment of charter schools, over 70,000 students in grades K-12 have enrolled in one of 135 “bricks and mortar” charter schools and a dozen cyber charter schools state-wide . In Philadelphia, one out of four students attends a charter school and the numbers are growing. Charter schools are created by parents, teachers, community leaders, and education management organizations. And while they have become a centerpiece in the school choice movement their very existence is the source of considerable debate. A new study by Stanford University’s Center for Research on Education Outcomes reports mixed results when it comes to student learning. Have Pennsylvania’s charter schools fulfilled their promise? Our guests include the report’s author DEV DAVIS , ROBERT FAYFICH of the Pennsylvania Coalition of Public Charter Schools, and education researcher GARY MIRON of Western Michigan University.