This new study which spans 3 years, 16 peer reviewed studies and involving over 120,000 students and faculty was recently published in the top tier journal Education Technology Research & Development. The study finds "the majority of faculty and students who have used OER had a positive experience and would do so again."
This present study synthesizes results from sixteen efficacy and twenty perceptions studies involving 121,168 students or faculty that examine either (1) OER and student efficacy in higher education settings or (2) the perceptions of college students and/or instructors who have used OER. Results across these studies suggest students achieve the same or better learning outcomes when using OER while saving significant amounts of money. The results also indicate that the majority of faculty and students who have used OER had a positive experience and would do so again.
From the conclusion: "more than 95% of published research indicates OER does not lead to lower student learning outcomes, and the vast majority of students and faculty who have used both OER and CT believe OER are of equal or higher quality make it increasingly challenging to justify the high price of textbooks."