A good OER is:
While the adoption of OER may prove beneficial, the normal practice of critical evaluation is even more important. For example, in the context of textbooks, the publisher is responsible for conducting a rigorous editing and proofreading process to ensure a high standard of quality, usability, accessibility, and accuracy.
The decision to adopt an OER places the responsibility on you to ensure the quality, integrity, usability, accessibility and accuracy of the resources for teaching and learning purposes. You must be confident that the OER will meet the teaching and learning goals and objectives.
Evaluation methods vary and include a crowd-sourcing approach where users rate the text, analyse usage logs to identify patterns, and adopt quality rubrics. Concerning the latter, rubrics designed to evaluate OER quality often consist of several dimensions or indicators, with each dimension or indicator measuring one aspect of OER quality. Research has examined various rubrics, including ACHIEVE OER, LORI and GEM and identified a range of quality indicators that provide a useful analysis framework (Yuan & Recker, 2019). Such indicators include:
OER Commons Submission Guidelines
This series of short OER Bootcamp videos from Sarah Morehouse provides very practical tips when considering to use an OER.