When I was in elementary school, we had something called an "Individualized Learning System" (or something like that), where the kids in my class all covered the material semi-independently at our own speeds. It seemed like it worked pretty well, but it disappeared when we got to middle school, and I think it was entirely discontinued in the school district shortly after that. Coincidentally, or not, my grades went from straight-As to barely passing after elementary school. I hope the essay is right, and we see a technology-driven return to that style of learning.