OER stands for Open Educational Resources, and is a term that refers to any educational resources that are typically:
Open Textbook is a specific type of OER that is designed to be a free or low cost substitute for a traditional textbook.
A: Many open resources do provide test banks (and power points, and other supplementals we're used to getting from a publisher). To answer the question about "protected resources" we went to Nicole Finkbeiner, Associate Director of Institutional Relations, Rice University's OpenStax College:
"In terms of "protected" resources such as test banks, you have to find a way for students to not be able to access these. And, you don't want to openly license these because then you have no way to combat them being published. At Rice University’s OpenStax College, our website is set-up so faculty have to first register for an account and then request faculty access prior to being able to download them. We check every single account to ensure the right official email is used, they are in fact teaching a course where they would need the resources, etc. Sometimes we even call the department chair directly to make sure we should be providing access, so this is definitely a labor-intensive process, but I think it is worth it to protect the resources.
Faculty should also be very careful not to post any protected OER resources in a public environment, such as a website."
A: It's true that adopting open resources in place of a traditionally published textbook involves a change in how you think about your course textbook. Adopting OER involves a feeling of ownership of the course resources that you might not experience with a traditional textbook. Because of the open licensing you are free to update the material as you see fit, as long as it has the appropriate Creative Commons licensing. Due to the open nature of these resources, collaboration with other instructors (within our outside this institution) or with your students to improve the open resources you use is a common occurance, and means the work of updating is spread across many people instead of sitting solely with you. Yes, it's a shift of perspective, but it's an exciting one, full of potential.
Also: there are a growing number of open textbooks that have the kind of publisher services faculty expect, with regular updates, printed and bound copies available for purchase, test banks and other instructor supplementals. See especially OpenStax and BCCampus.
Do you have a question about OER? Please ask!