@yminsky -- yep, taxonomies r hard :) but i'm trying to go as much as possible by what each department proclaims for itself rather than trying to calibrate across departments. If Harvard calls a class "Computer Science II", I'm going to consider it as CS2. (fwiw I consider Harvard CS50 a hybrid of CS0 and CS1 since students voluntarily split themselves into two tracks called "less comfortable" and "more comfortable", respectively.)