This was his first class at UCLA, so he definitely wasn't the greatest lecturer, however, he was clearly very caring for his students and could be quite funny during lectures. His exams were extremely straightforward and I did well up until the final which I hardly studied for and rightfully did terrible on, which dropped my grade from a comfortable A to barely a B. Overall, I only expect Haoren to get better as a lecturer and I would definitely recommend him for this class.

Underrated in my opinion. He goes through material in an efficient and clear manner, and releases homework every lecture (just a few questions). Furthermore, his lectures (at least during fall 2022) were recorded, so you didn't have to attend lectures physically at all. His practice midterms are extremely similar to his actual midterms, so I would recommend doing them.

Overall, I have found this course to be very enjoyable and informative, and Haoren is an excellent lecturer who explains the material very clearly. I especially appreciate that he provides helpful notes that are useful for reviewing, and that he always uploads the lecture recordings on time. Based on my experience, I would highly recommend him for 31B.

However, I did find the final exam to be quite challenging, even though I thought I had prepared well and was hoping for at least an A-. Unfortunately, I ended up with a B+ instead. On the other hand, the midterms were much more straightforward and closely resembled the practice exams, so I found them to be manageable with sufficient preparation. For anyone planning to take this course in the future, I would suggest being aware that the final exam may be more difficult than the midterms, and taking extra time to prepare accordingly.

This is his first lecture ever taught, and I'm surprised by how fast he improved his style of lecturing. His exams weren't the easiest, but if you study hard you will end up with a good grade. Definitely would take another course with him.

Honestly, you are just teaching yourself everything. The professor reads and explains very poorly actually he does not explain. The exams he makes are very complicated and include things that he does not even go over, which is very frustrating. When the class does badly, he writes a message to the students about how badly we did. I took him last quarter too for 31 AL and he said "I went through this and suffered now it is your time to suffer" just to show that he does not care.

Haoren is a kind person and I think it is possible to do well in his class. I took this class my first quarter here and his first quarter at UCLA. I came in having done well in AP calculus AB (I got a 5 on the exam and did really well in the class). The content's logic level was similar to the material from calc AB(and I assume 31a). However Haoren's teaching method was very difficult to understand--I do best when I am plainly told which methods to use for which problems. In each class, Haoren simply started solving different problems while vaguely narrating each step with out explaining why. It felt like he was reading from the textbook. When students asked questions, he would give a quick response and then keep solving without checking to see if his explanation made sense. Sometimes when people asked him why he was doing something, he would say, "this is just what the textbook says". My TA, Zerrin Vural was great. During discussion, she would explain things in a way that made much more sense to me! Also each lecture was very similar to the textbook, so towards the end of the quarter, I started reading the textbook before lecture which helped a lot. The lectures are also recorded and he doesn't keep track of attendance. Haoren's office hours were also really helpful because he would show how to solve confusing problems from the homework and practice midterm--I found these more helpful than the lectures. The class was well organized and I felt that the tests were very similar to the practice tests. I think that I did so poorly, not only because of the teaching style, but also because of a mix of the TA strike, being overloaded by my other STEM classes, having the midterms returned 2 days before the final, and being new to UCLA. Still, I think I would have been able to get higher grades with less effort with a different professor. I would recommend trying to take the class with a professor who has more experience teaching/is better at explaining things. I know a lot of people are struggling in his 31AL class right now as well. If you do take this class, I recommend going to office hours and making sure that you understand everything in the practice midterm.
Also here is how it was graded:
15% Homework-graded on correctness, 2 lowest homework scores dropped
There are 2 midterms and a final
There are 2 Test Grading Schemes--they will chose whichever is higher
A: 20% each midterm, 45% final
B: Highest of the two midterms for 30%, Final 55%

Professor was helpful in-lecture, though he goes through material somewhat quickly. Practice midterms accurately reflect the actual midterms, but the practice final does not accurately reflect the actual final (the actual final is way harder.)

The professor is kind of just there. His lectures are not very helpful. Organic chemistry tutor and other online resources do a far better job at teaching the concepts. I'm sure Professor Xiong is brilliant, but it begs the question, why we are paying to learn from a sub-par instructor when we have free content online that covers the whole course? The professor is not terrible, but not good. Midterms were not bad, but he decided to screw people on the final. He chose more difficult problems that we didn't have as much practice with, and included a practice final that was definitely easier. I'm almost certain that he said that the practice final was going to be harder, and that if we did well on that, we would be set for the final. It was the opposite. There is no value in taking this class with this professor. It seemed like he was just clocking in.

In my opinion, the professor really had no impact on how I performed in this class. While Xiong is really nice and is always open to answering questions from students, there it ultimately not much to be gained by attending lectures, which you realize after attending a few. The lectures are very proof-heavy, which is great if you're interested in that kind of stuff. However, if you're like me and are only taking this class to fulfill a requirement, it doesn't make sense to know those things. 90% of the content in lectures won't be tested, you only need to know how to do the example problems. Lectures are recorded so I stopped attending lectures 3 weeks in, but I was still able to get an A by using online resources (my lord and savior The Organic Chemistry Tutor) and attending discussions/review sessions. Weekly discussion sections weren't mandatory, but I found them to be extremely helpful. My TA Cecelia was amazing and I definitely owe it to her that I was able to do well in this course. I highly recommend attending discussions, office hours, and review sessions organized by the TAs.

In terms of the workload, this class has one of the lightest workloads ever. There are 7 assignments total, each due a week or two apart. Each one has fewer than 10 questions, and problems are gradually assigned over the course of the week (2 or 3 after each lecture) so it's really easy to space them out and manage your time.

The grading scheme is very test-heavy, which is to be expected from most math courses. However, the midterms were not too bad, especially since Xiong provides practice midterms which are very similar in content and difficulty as the actual midterm. Unfortunately, the same can't be said for the final. Though a practice final was provided, the actual final was significantly harder and there were some curveball questions. I recommend doing the practice midterms (time yourself and take them like you would take a real midterm) because they will give you a pretty accurate idea of where you're at.

Honestly, how well you perform in this class is really just based on how good you are at math. You will probably have to teach yourself the entire curriculum, but it was manageable in my experience.

Mr. Xiong is not a very effective lecturer, relying mostly on his notes and students' prior knowledge. His lectures are seldom engaging and I felt more prepared afting reading the textbook than attending his classes. Despite this, his class is structured (in terms of grading scale and homework) relatively well, and I do appreciate his willingness to answer questions and help students. My overall experience with the class has been lukewarm but it is definitely not the worst you could do.