Any teaching will be done a hundred fold better if you can organize your material linearly, we love to think in a line, we love the next/prev option when exploring new grounds. It gives us comfort that we won't be lost. Why? for the same reason we can intuitilvy understand the physical world in three dimensions. A graph is cool, but a line is more comforting. It's added bonus if they know the whole line is included in what you're offering. They'll understand everything you say, and everything you say is everything they need to know.
