Just like making an assessment of a textbook or reading you would assign for a course, evaluating if an OER is appropriate for your teaching is important. If you are reviewing or rewriting your syllabus for online learning, these basic principles will help guide your decision-making.
Where you found the resource - If you used one of the tools in the Discovering OER section, the content you're reviewing is definitely OER and can be used as such, but if you're on the open web, you'll need to look at the usage statements or licenses before you adapt the material for your course.
Author's Qualifications and Affiliations - Many OER are authored by other instructors or professors in higher education, but others are not. Consider who created the OER before you use it.
Date of Publication/Currency - Since OER are generally not produced by large publishing companies that often release new editions, it is important to assess when an OER was created and how recently it has been updated. You can make updates yourself, but checking the date of publication is important in deciding if a material is current enough for your course.
Intended Audience - OER can be produced for any age and audience, so sorting in a tool by education level is critical. Some open textbooks are for 101-type classes while other materials are designed for very topic-specific courses. You can always edit an OER to better suit your students, but an appropriate starting point is usually desirable.
Documentation of Sources - Like any other teaching material, some resources will be better documented than others. When it comes to reusing OER or in most other scholarly circles, attribution is necessary. Searching for the sources in an OER shouldn't consume all of your evaluation time, so finding something with proper citation can save you some effort.
Bias - It goes without saying that students at a university would need to interrogate the bias of a source in their studies. This tenant would be applicable to any closed educational resource as well.
Suitability of the Work for your Purposes - Since many OER are online exclusively, you'll need to ensure that you have stable access to them as URLs change and materials are updated by their authors. Making copies with your own edits or finding DOIs or other stable links can be critical for using an OER over several iterations of your course. For more information on DOIs see doi.org.
Review and Curation Process - Is the resource you're considering peer reviewed? If it is not—as many OER aren't—then you can assess the authorship authority again. As stated about currency of materials, it could be useful to look for information on how often, if at all, an OER is updated.
Restrictions/Licenses of the Work - Licensing is a critical aspect of what makes an OER an OER. They are designed to be reused and remixed by others. Looking for Creative Commons licenses or other statements of use permissions will inform your ability to use the resource.