I had a really good survey of automata professor tell us that we could buy the textbook if we wanted, but if we read the slides and/or reviewed taped lectures,

I had a really good survey of automata professor tell us that we could buy the textbook if we wanted, but if we read the slides and/or reviewed taped lectures, the textbook would be completely optional. I think the sign of a good educator is when the teacher provides materials that are decoupled from the textbook. I like the idea of making the textbook optional. Of course, this means more work for the instructor (need to develop homework, lectures, supplemental reading/slides). And a lot of instructors in university didn't care to do this work.