Free or low-cost: OER programs report saving students millions on the cost of education. Low costs mean fewer barriers for students to succeed.
Customization: Faculty members can customize their class instruction for their students. David Wiley, open education proponent, argues compellingly in "iterating toward openness" that OERs can facilitate more meaningful, more inclusive pedagogical practices.
Increasing support for "plug and play" resources: For instructors who have little time to adapt resources, open education projects like OpenStax and the Open Learning Initiative (Carnegie Mellon) are increasingly making "packaged" resources available. Packaged resources include textbooks with accompanying ancillary resources (slides, clicker exercises, learning materials) and entire courses and course modules.
Student-driven, multimodal learning: OERs are one way of engaging students more deeply in the educational process, moving beyond lecture and text. Open education gives instructors the tools to involve students in the creation of learning materials. See, for instance, this cluster of projects at North Carolina State University--one of which involved students making lab videos for future students in lieu of purchasing a laboratory text.
Lifelong learning: Because OERs are open, they allow students to return to course content again and again--before and after courses.
Permanence: Digital information--including OERs--can disappear if it's not archived and backed up in a trusted repository.
Potential corporatization: Corporatization is one reason for the sharp rise in cost of educational materials. There is concern that as companies like Amazon take on OERs, they will also monopolize or otherwise limit the openness of the open education model. For more on this issue, see this statement by the International Publishers Association and this counterpoint.
Complex IP issues: Although OERs use open licenses in part to reduce complexity around intellectual property, issues do arise. Open licensing in itself can be a challenge to navigate; in addition, third-party materials like media and images may introduce complexity into any OER project.
Missing ancillary resources: Although some OER projects like OpenStax are working to incorporate more resources for instructors and students, other open resources lack instructor copies, outlines, quizzes/tests, clicker exercises, and other materials that can make publisher offerings attractive.
Quality issues: OERs may be produced with little added support for copy-editing and design. In addition, some may not be updated as frequently as the education community might like. For more about evaluating OERs, see this toolkit by JISC. Another project that is addressing quality issues in OERs is Open Textbook Library at the University of Minnesota. The Open Textbook Library allows educators to review open textbooks using a rubric citing ten criteria.
Time: Creating and/or locating existing OERs can be extremely time-consuming. For this reason, libraries, administrators, and instructional designers at various institutions are increasingly providing support for faculty members who wish to use OERs in their courses.