Research on OER impacts are not confined to cost savings estimates. There is a growing body of knowledge and research about the impacts OER have on student outcomes. Studies look at student satisfaction, engagement and outcomes as measured by completion, retention, drop/failure/withdrawal rates, and grades. There are large scale studies and class level case studies at various types of post secondary institutions. Some of this research has even been incorporated into a OER Adaption Impact Calculator. The Open Education Group, a grant funded organization devoted to enhancing open education, had developed a framework for understanding the impact of OER
Listed here are only a few such studies with links to a feed for new papers.
Colvard, N. B., Watson, C. E., & Park, H. (n.d.). The Impact of Open Educational Resources on Various Student Success Metrics. 15. https://files.eric.ed.gov/fulltext/EJ1184998.pdf
Fischer, L., Hilton, J., Robinson, T. J., & Wiley, D. A. (2015). A multi-institutional study of the impact of open textbook adoption on the learning outcomes of post-secondary students. Journal of Computing in Higher Education, 27(3), 159–172. https://doi.org/10.1007/s12528-015-9101-x
Hilton, J. (2016). Open educational resources and college textbook choices: A review of research on efficacy and perceptions. Educational Technology Research and Development, 64(4), 573–590. https://doi.org/10.1007/s11423-016-9434-9
Hilton III, J. L., Gaudet, D., Clark, P., Robinson, J., & Wiley, D. (2013). The adoption of open educational resources by one community college math department. The International Review of Research in Open and Distributed Learning, 14(4). https://doi.org/10.19173/irrodl.v14i4.1523
Lawrence, C. N., & Lester, J. A. (2018). Evaluating the Effectiveness of Adopting Open Educational Resources in an Introductory American Government Course. Journal of Political Science Education, 14(4), 555–566. https://doi.org/10.1080/15512169.2017.1422739