Do you find you have more interest in the mechanics of grammar now that you see its applicability? I remember in high school I couldn't care less about history. I knew in an abstract sense that there was benefit in learning history, but to me it seemed not nearly as fascinating as English, mathematics, or music, all subjects which I naturally enjoyed. I agree that it seems unlikely that self-directed study will provide the "hook" that a passionate teacher might to draw students in to the excitement of learning subject material. But, I do think it is a useful tool, especially for those students who already have a knack and drive for the material. As an undergrad music major, I had trouble learning ear training skills, and had to drop my music theory class. What helped me grasp the material was working on ear training over (and over and over) in the computer lab using a software called Auralia. It helped so much that no one saw how many answers I missed! After many iterations of intervals I picked up on how to listen. I think adaptive learning is especially beneficial in this type of scenario, where I needed a bit of extra practice, one that would not be feasible to provide in a classroom setting.
