Olaf Zawacki-Richter is a Professor of Educational Technology at the University of Oldenburg (Germany), where he teachers at the Faculty of Education and Social Sciences and the Centre for Lifelong Learning. From 2008 to 2010, he held a fixed-term professorship in Educational Technology at the FernUniversity in Hagen, Germany's Open University. He serves on the editorial board of the International Review of Research in Open and Distributed Learning (IRRODL), Distance Education, Open Learning and the Open University of Sri Lanka Journal. He has been an invited keynote speaker, chair and reviewer at many international conferences. Together with Terry Anderson, Professor Emeritus at the Centre for Distance Education, Athabasca University, Canada, he edited the book Online Distance Education: Towards a Research Agenda. He also co-edited Open and Distance Education in Australia, Europe and the Americas: National Perspectives in a Digital Age, with Adnan Qayyum. He is Director of the Center for Open Education Research.Adnan Qayyum is an Assistant Professor of Lifelong Learning and Adult Education at the Department of Learning and Performance Systems, Pennsylvania State University. His areas of expertise include open and distance education, adult education, comparative and international education, instructional design, curriculum planning, educational planning, and evaluation. He is an Associate Editor for the American Journal of Distance Education, and was formerly an Associate Editor for the international journal Distance Education. Together with Olaf Zawacki-Richter, he edited Open and Distance Education in Australia, Europe and the Americas: National Perspectives in a Digital Age. He is a founding member of the Center for Open Education Research.