Why use OER?
"In total, more than 25,000 students have utilized OER materials across the studies that attempted to measure results pertaining to student efficacy. These students results were compared with approximately 100,000 students using traditional textbooks. While causality was not claimed by any researcher, the use of OER was sometimes correlated with higher test scores, lower failure, or withdrawal rates. In only one efficacy study did more students do worse than did better, and even in that study the majority of students achieved the same results as their peers using traditional textbooks."
-- From the ongoing Review Project led by John Hilton III which reviews OER studies that focus on efficacy and perceptions of OER.
Since OER are meant to be adapted so courses can be customized around student needs.
"[R]esults of a large-scale study (21,822 students)... indicate that OER adoption does much more than simply save students money and address student debt concerns. OER improve end-of-course grades and decrease DFW (D, F, and Withdrawal letter grades) rates for all students. They also improve course grades at greater rates and decrease DFW rates at greater rates for Pell recipient students, part-time students, and populations historically underserved by higher education."
-- From Colvard, Watson, and Park's 2018 article The Impact of Open Educational Resources on Various Student Success Metrics.
" 57% of students stated that they did not purchase a textbook for at least one course because of the cost, 25% said they had registered for a different section of a course, 19% said they had taken fewer courses than they would have liked, and 16% said they had dropped or withdrawn from at least one course." This is not surprising given the increasing costs of college textbooks.
-- From Hendricks, Reinsberg, and Rieger's 2017 article, The Adoption of an Open Textbook in a Large Physics Course: An Analysis of Cost, Outcomes, Use, and Perceptions.