How are students added to a course?

In Washington State, mostly colleges and universities will integrate Canvas with their student records management system. For community and technical colleges this system is currently known as SMS. Universities will have a different solution. For instance; at EWU they use Banner. Each institution will have it's own policy about how students are added to courses and may or may not allow faculty members to manually add students to courses. The information that follows is relevant where instructors do have this prerogative.