How do you tell if an educational resource is an OER?

Answer:

The key distinguishing characteristic of OER is its intellectual property license and the freedoms the license grants to others to share and adapt it. If a lesson plan or activity is not clearly tagged or marked as being in the public domain or having an open license, it is not OER. It’s that simple. The most common way to release materials as OER is through Creative Commons copyright licenses, which are standardized, free-to-use open licenses that have already been used on more than 1 billion copyrighted works.