The Open Education Group is an interdisciplinary research group that (1) conducts original, rigorous empirical research on the impact of OER adoption on a range of educational outcomes and (2) designs and shares methodological and conceptual frameworks for studying the impact of OER adoption. See some of their publications and their review of empirical research on the impacts of OER adoption.
The "big picture" of OER including how content can be shared, reused, and remixed by educators. Open Education Matters: Why is it important to share content? was created by Nadia Paola Mireles Torres, licensed under CC BY 3.0.