“…For example, OER allow teachers and students to remix content in locally meaningful ways (D'Antoni, 2009), to share a variety of types of learning resources (Downes, 2007), and to enable the best resources for teaching a specific topic to be more easily found (Gurrell & Wiley, 2008). OER have received considerable attention in higher education (Baker, 2005;Koch, 2006), and researchers are examining the question of how students are receiving open textbooks and how these textbooks affect student learning (Frith, 2009) Curriculum materials are an important part of student learning and represent a significant, recurring cost to public schools (Ansari, 2004). In the United States, core high-school science textbooks (without supplemental materials) from commercial publishers available on Amazon.com cost $80-$120 per copy, and teacher editions typically cost over $100 per copy.…”