It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
Research shows that "Students in the OER sections were retained and persisted at a statistically significant higher rate, lending credibility to the findings of former studies regarding retention and persistence rates in courses taught with OER materials" (Bol, 2021).