That's a good point, and certainly an argument for intermediate courses being directly linked to novice courses which cover the prerequisites. I believe there'

That's a good point, and certainly an argument for intermediate courses being directly linked to novice courses which cover the prerequisites. I believe there's also a factor that intermediate knowledge requires much more of a conceptual grasp. Selecting or joining on the correct columns is one thing, but actually knowing when to use what operation and which might have better performance means you need an intuition about the data structures. This is much harder to teach, and probably the only really good way is to get people to attack lots of problems set at the right level of challenge.