2Kortemeyer G.Ten years later: why open educational re- sources have not noticeably affected higher education, and why we should care [ J ]. EDUCAUSE Review, Online, 2013:02-26.
3Zemsky R. With a MOOC MOOC here and a MOOC MOOC there,here a MOOC,there a MOOC, everywhere a MOOC MOOC [ J]. The Journal of General Education, 2014,63(4) :237-243.
4Xu D,Jaggars S S.Performanee gaps between online and face-to-face courses: Differences across types of students and academic subject areas[ J] .The Journal of Higher Ed- ucation, 2014,85 ( 5 ) : 633-659.
5Means B, Toyama Y, Murphy R, et al. Evaluation of Evi- dence-Based Practices in Online Learning: A Meta- Analysis and Review of Online Learning Studies[J]. US Department of Education, 2009.
