1. Faculty of Foreign Languages, University of Shanghai for Science and Technology, Shanghai, China
2. Big Data Centre for Technology-Mediated Education, Beijing Normal University, Beijing, China
3. Research Centre of Distance Education, Beijing Normal University, Beijing, China
4. Faculty of Educational Sciences, Open University of the Netherland, Heerlen, The Netherlands
5. School of Systems Science, Beijing Normal University, Beijing, Haidian District, China