In the largest study of its kind, a group of researchers has examined the use of open educational resources (OER) and found that students who used OER in their undergraduate courses performed as well or better than those assigned commercial textbooks. The project was undertaken by researchers from Brigham Young University, the Michigan State Department of Education and Lumen Learning, a not-for-profit focused on the use of open courseware. The study involved 5,000 students using OER and more than 11,000 "control" students using standard textbooks in courses at 10 different institutions around the country enrolled in 15 different undergraduate courses.
https://campustechnology.com/articles/2015/11/10/major-study-finds-oer-students-do-just-as-well-or-better.aspx
