<p>classes totally vary in size. ECO 100 and 101 lectures are huge (i think the class has something like 300 ppl, not that evyerone goes to the lecture) most lectures have about 60 ppl or so, but really as long as its a lecture class it doesnt really matter the size. Theres also always a precept which allows for smaller class sizes and discussions. Seminars are usually small. I'd try to take a mix of larger lectures and smaller discussions because its sometimes nice to be able to skip a class if youre really busy (and seminars are akward to skip), but its also nice to have the discussion</p>