MK213 Principles of Sales This course is exemplary as a 100% Open Education Resource (OER) based online course. Further,, the course has been designed for maximum accessibility, based on best practices and principles of Universal Design for Learning (UDL). Active and collaborative online assignments that draw on Mr. Grenier’s decade of online teaching and instructional design experience are a mainstay of the course, including growing use of innovative interactive OER (iOER) materials.