Much has been done to furnish lower-division and general education mathematics courses with OER options. In the realms of algebra and calculus, for example, there now exists a wealth of excellent open resources that can be easily adopted by math instructors and students. That said, there is still room for quality improvement in many subjects, including trigonometry, liberal arts math, and finite mathematics. Because of the freedom and flexibility afforded by OER, it’s easy to imagine new opportunities for curricula targeted to different disciplines: calculus courses for life sciences, business, or geology, for example. Although a few of these kinds of targeted texts exist, improvements and additions are needed.
Upper-division mathematics are where the greatest shortage exists. Though there are some very strong textbooks available, upper-division math courses are far less standardized across the US. An abstract algebra course at one institution might differ substantially from the same course at another. Similarly, there are many more perspectives on teaching college geometry as compared to college algebra; OER affords those different, important voices a platform. Even if an educator does not want to write her own text, OER allows her to customize an existing text to her individual teaching style and course curriculum in a way commercial textbooks cannot. Ultimately, many more upper-division textbooks need to be developed to offer adequate variety and diversity for the faculty who will consider adopting them.