The MacArthur Report Series in Digital Media and Learning are commissioned white papers focusing on concepts and topic areas key to the understanding of digital media and learning. The series is published by MIT Press and edited by Ellen Seiter, Professor of Critical Studies, USC School of Cinematic Arts. The Digital Media and Learning Research Hub Reports on Connected Learning are made possible by grants from the John D. and Catherine T. MacArthur Foundation in connection with its grant making initiative on Digital Media and Learning. To contact Professor Seiter about authorship opportunities, email eseiter@usc.edu.