Guang Cheng is not a good professor. But, he is pretty clear when teaching straightforward and easy concepts in weeks 1-4, however, he fails to teach the second half (pdfs, cdfs) well because he explains none of the notation to students and expects them to follow along.

Outside of that, there are some serious problems with his course structuring. He teaches the first four weeks extremely slowly, and I would say that the content at this time is not difficult and should be taught in 3 weeks. The midterm is also torturously easy, with the mean and median both being above a 90. Then, he rushes through the significantly harder and more applicable content in the second half of the quarter. With my class, he rushed through variance, covariance, and MGFs in the last three lectures before the final. Additionally, he was out of school, leaving the quiet and unengaging TA to teach expectation within a week (two lectures). In the end, his final exam was so difficult that the average was like a 50 and he didn't curve it. I scored in the upper quartile and ended with a 65 or something like that. In the end, even though I was in the upper quartile for both the midterm and the final, I ended the class with a B, which felt really bad because I put in a lot of work and also did significantly better than my peers but got a grade that didn't reflect that.

Professor Cheng does not care about his students. DO NOT TAKE HIS CLASS IF YOU HAVE ANY OTHER OPTION. The professor hands out SELECTIVE grade bumps, does not respond to emails, and requires department intervention to be forced to communicate with his students.

His lectures are extremely theoretical, and don't help with understanding the homework. His final average was 54% with no curve, and no explanation. Seriously, do NOT take his class.

He claims to be a "busy" professor and that's why he can't communicate with his students. He refuses to set up an appointment unless it is weeks in advance. Very unprofessional.