Grimaldi, Phillip J.Mallick, Debshila BasuWaters, Andrew E.Baraniuk, Richard G.2019-12-112019-12-112019Grimaldi, Phillip J., Mallick, Debshila Basu, Waters, Andrew E., et al.. "Do open educational resources improve student learning? Implications of the access hypothesis." <i>PLoS ONE,</i> 14, no. 3 (2019) Public Library of Science: https://doi.org/10.1371/journal.pone.0212508.https://hdl.handle.net/1911/107850Open Educational Resources (OER) have been lauded for their ability to reduce student costs and improve equity in higher education. Research examining whether OER provides learning benefits have produced mixed results, with most studies showing null effects. We argue that the common methods used to examine OER efficacy are unlikely to detect positive effects based on predictions of the access hypothesis. The access hypothesis states that OER benefits learning by providing access to critical course materials, and therefore predicts that OER should only benefit students who would not otherwise have access to the materials. Through the use of simulation analysis, we demonstrate that even if there is a learning benefit of OER, standard research methods are unlikely to detect it.engThis is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Journal articlejournal.pone.0212508https://doi.org/10.1371/journal.pone.0212508