<p>For really small class sizes, you should have chosen Liberal Arts colleges. A lot of colleges like CMU and Tufts, the introductory classes are 100+ students. Yes, this is true even at Stanford.
Berkeley does have small group discussion based sections, I have heard. If you need a lot of hand-holding maybe Berkeley will overwhelm you . But for natural and social sciences, I would still stick with Berkeley. Here is an old thread that mentions Tufts class sizes in the thread <a href=“Actual class size in humanities, social sciences - McGill University - College Confidential Forums”>http://talk.collegeconfidential.com/mcgill-university/915312-actual-class-size-in-humanities-social-sciences.html</a></p>