Can we count corporate, Government information films, and short documentary/information films as "independent films"? It's worth thinking about. Students will need carve out a definition of what an independent film is so that they can make boundries and show that such definitions are problematic for their essays. They will also need to establish the degree of independence that exists from mainstream film-makers. That, too, is very problematic.
Of course, strong reference to case study films will enable students to make detailed points on independent films and their audiences.