A little hard to understand Prof Xiong's accent but you get used to it. The midterm and final were all similar to the practice ones he gave us. Overall I found the class pretty good and liked it. I would recommend taking it with Prof Xiong

This class is hard, obviously, but I loved haoren. He was so funny and clearly cared about us and our learning. There was weekly (ish) homework that he usually went over in office hours which was a little tricky, but if you asked him to go over it he would. The lectures were basically textbook, but he used some new examples and explained a bit better than the textbook. There were 2 midterms, one could be dropped if it helped your grade, and he gave us practice midterms that were extremely similar to the actual midterm. He did review sessions on the weekend before finals and all office hours and lectures were recorded. I got 80% on the first midterm, 86% on the second, and a 72% on the final. Grade was a B- in the end and it was curved to a B. If you are taking this class I would highly recommend haoren especially after hearing stories from my friends with other 31b professors.