Many are behind paywalls, but... let's just say there are ways around those. http://onlinelibrary.wiley.com/doi/10.1111/jcal.12131/full http://onlinelibrary.wi

Many are behind paywalls, but... let's just say there are ways around those. http://onlinelibrary.wiley.com/doi/10.1111/jcal.12131/full http://onlinelibrary.wiley.com/doi/10.1111/jcal.12131/full http://onlinelibrary.wiley.com/doi/10.1002/aehe.20018/full http://onlinelibrary.wiley.com/doi/10.1002/aehe.20018/full https://dl.acm.org/citation.cfm?id=2835842 https://dl.acm.org/citation.cfm?id=2835842 http://www.irrodl.org/index.php/irrodl/article/view/2112 http://www.irrodl.org/index.php/irrodl/article/view/2112 https://www.openeducationeuropa.eu/sites/default/files/legacy_files/asset/From-field_37_6.pdf https://www.openeducationeuropa.eu/sites/default/files/legac... http://www.educationaldatamining.org/EDM2014/uploads/procs2014/short%20papers/273_EDM-2014-Short.pdf http://www.educationaldatamining.org/EDM2014/uploads/procs20...