I don't think Khan claimed about teaching expert level material. `Superficiality` is a strong word. Zed Shaw's LPTHW is for beginners, but not superficial. Sim

I don't think Khan claimed about teaching expert level material. `Superficiality` is a strong word. Zed Shaw's LPTHW is for beginners, but not superficial. Similarly, most of Khan's lectures target a particular audience. Some of his lectures are advanced, some are intermediate, some are for beginners...just the way it should be. Khan himself responded to one of superficiality claims here on HN(the one about history lessons).