At #OpenEd14 John Hilton presented a summary of all the empirical research on the impact of OER adoption that we could find. The presentation was extremely well received, and John has turned it into a nice journal article which is currently under review at a journal which shall remain nameless (for the time being).
By the time the article appears, however, it will almost certainly be out of date. As a service to the field, we’ve published an abstracted version of John’s article on the OEG website under the label The Review Project. We’ll keep this page up-to-date as we come across additional articles that actually take a solid empirical look at the impacts of OER adoption. Do you know of one we’ve missed? Head over to The Review Project and leave a reference in the comments.