1. College of Teacher Education, Zhejiang Normal University, Jinhua, China
2. National Engineering Research Center for E-Learning, Central China Normal University, Wuhan, China
3. Department of Educational Technology, Boise State University, Boise, ID, USA
4. National Engineering Laboratory for Educational Big Data, Central China Normal University, Wuhan, China
5. Department of Educational Studies, University of South Carolina, Columbia, SC, USA