1. Smart Learning Institute of Beijing Normal University, Beijing, People’s Republic of China
2. School of Education, University of California, Irvine, CA, USA
3. Distance Education Department, Open Education Faculty, Anadolu University, Eskişehir, Turkey
4. Department of English Studies, College of Human Sciences, University of South Africa (UNISA), Pretoria, South Africa
5. Instructional Systems Technology Department, School of Education, Indiana University, Bloomington, IN, USA
6. Research Institute of Education Science, Hunan University, Changsha, People’s Republic of China