Professor Michael Tsiang's lectures and slides are very helpful because he breaks everything down in order for it to be easy to understand. His exams are not easy A's however as you will find trick questions or oddly-worded questions causing you to get a B or B+ on his exams instead. But don't worry!!! I was below the mean on the first mid-term, but quite above the mean on the next mid-term and final. As long as you guys make sure you are at the mean for every exam, YOU WILL GET AN A! In addition, he gives very generous extra credit opportunities, which I made sure to capitalize on, make sure you do too. Although this class might make you stress out a bit, as long as you put in your effort, it is an easy A. I wish all his future students the best of luck. YOU GOT THIS!!!

** During the pandemic **
I really liked Mike, his lectures, and his detailed notes. It's clear that everyone involved (the professor, the TA, and the LA) put a lot of time, effort, and straight up love into running and fixing up this class. The Campuswire environment felt super student-friendly, and I felt like I learned a lot without too much stress -- I just followed along with the lectures at the end of every week, did the homework, and scored in Q4 and Q3 on the two midterms. These guys are Gs are did a really good job organizing the class this quarter, especially for the pandemic. I will 100% try to take another class with Mike if I can :)

The workload in this class is overwhelming and Mike and the TA Jake have the typical air of "this isn't difficult, why are you struggling to understand this?" when the majority of people taking the class have never used R before. I never felt like the lecture notes adequately prepared me for the weekly homework assignments, and definitely not for the exams. The final project was assigned in the middle of week 9 when it was supposed to be assigned week 7, and was originally due the day after our final. So naturally, I spent a lot of my time leading up to the final working on the project. Right before our final started, he said he would be fine with people submitting the project on Sunday. I would have rather had more time to study for the final and then work on the project during the weekend if he had mentioned this change earlier.

As of Fall 2019 this class is no longer reasonable. The class is clearly meant to weed students out of the statistics department and honestly, its working. The workload is entirely unreasonable (10- 15 hours per homework assignment, at times multiple homework assignments per week, 70% average on homework grades), tests are impossible (45 minutes for multiple choice and multiple coding free responses, 58% average on the first midterm), and professor Mike and TA Jake are extremely rude and unhelpful (condescending and will not answer questions). Do yourself a favor and do not take this class.

The workload is insane. Everyone took this course previous quarters told me this was an easy course, but not anymore. It really just takes all your study time. The exam is really ridiculous. People seem they might have no enough time to finish all the questions in 45 minutes. There are 15 multiple questions and two free responding questions that are subdivided by two, which are expected to be done in 45 minutes. Weekly homework is intensive as well. I really do not know why they make the homework unnecessarily hard even though they know most of the students in this course are mainly STEM majors who need to do other assignments too. Re-writing built-in functions in your own code is just time wasting and really useless. There are always time consuming and crazy problems that are time-consuming and depressing. One of the TA's named Jake unnecessarily yells at students when testing time is up, and the professor emphasizes mental well-being. HA! It is really all oxymoron. This course gives you depression for real. I don't know how he was previous quarters, but this is the worst course by far.

This class is trash. I've taken the PIC classes, I have programming experience and this class is extremely difficult and you are docked points for the most random and dumbest things. When you ask questions, the TA or the professor will respond in an extremely condescending tone so as to ensure that you know you're an idiot. The midterms are hard as fuck, and the homework is tedious and extremely difficult. Don't take it, the grade distribution is misleading as it was before they seemingly changed the rigor of this class...

fuck the stats department

1.[Difficulty]: ★★★★(If you want an "easy-A GE class", this is IT! The midterms are a little bit tricky with an average score around 86, but the final is a relief. For the final, make sure you understand each material since some concepts are similar to each other and may be easily confused. However, the exams are moderate in difficulty and definitely manageable. There are labs, where you have to write codes and produce results with a computer. Since the TA's go through the answers almost step-by-step during the discussion, it's hard not to get a nice score out of this, so be sure to attend lab sessions. No homework, but there are online-quizzes, which are similar in difficulty with the examples he goes through in class. In addition to all these, Prof.Tsiang posts his slides and recordings of the lectures to the website, so that if you don't want to walk all the way to the classroom, you can still catch up by self-studying. All in all, an easy-A class, as long as you go to labs and pay attention to the concepts.)

2.[Workload]:★★★★(No homework, but have to do multiple-choice online quizzes which takes about 30 minutes per week. Labs are important, but you can get away with it by attending lab sessions and pay attention to the TA who basically gives you the solution.)

3.[Lecture]:★★★★☆(AMAZING! To be honest, attending Prof.Tsiang's lectures is a kind of enjoyment for me, since he goes through all important concepts so clearly and logically with detailed examples that it is hard not to understand the concepts after the lectures. Also, Prof.Tsiang goes to great lengths to make his classes as enjoyable and resourceful as possible, so definitely go to his lectures even if you can self-study with the notes he posts online.)

4.[Overall]: TAKE HIS CLASS at all costs. Prof.Tsiang's stats10 has been my favorite class at UCLA so far, and I reckon you will feel the same, should you choose to accept him as your professor.

I can definitely say that Stats 20 is currently in a transition period as Mike is looking to intensify the rigor of the class to best prepare Stats majors for the 102 series. What this means is that you can expect to spend a good amount of time doing homework and an end-of-the-quarter project. You can also expect to see written response questions in the midterms that can usually get brutal in difficulty as well as multiple choice questions that requires extensive playing around on R to learn specific outputs.

Personally, I recommend that you take a programming class such as Python beforehand. I took C beforehand, and still managed to struggle. Then again, knowledge of C does not translate well into R (Python is somewhat more similar to R). There were also some students with no programming experience that were in better shape than I was, but they probably have better study habits than me (I don’t recommend taking multiple shots of vodka while studying). But yeah, anyways, Mike is a real kind dude and he would try his best to help out his students on Campuswire and in office hours with hints. He won’t outright tell you the answers to homework problems, as he expects you to learn by struggling, but it does give you a better sense of accomplishment when you get a difficult function to successfully run.

I’m going to be frank, I did get quite stressed with the class and I usually manage to get my stress under control during the most trying times. I’m sure a lot of other people got heavily stressed too. The other reviews weren’t joking that there were multiple homework assignments around the time of the second midterm and the final project did get delayed until a week and a half before finals week, so that is something you will have to get prepared for. Combined that with the fact that I had a difficult Linear Algebra class to deal with and let’s just say I got pretty awful scores for my midterms and final. However, you can ask Mike if you can take your midterm at another time (I forgot to do this, oops) as he knows the period during the midterms is just downright tough.

In the end, I got a B+, and I don’t even think I deserved that grade at all. Mike was once a student like us, and graded very leniently since he knows how being a college student is a real ordeal. At the same time, he put us through quite a wild ride in this class in the hopes that we become ready for the upper division Stats classes. Because of that, I now feel ready to take on anything upper division Stats classes toss at me, and I’m optimistic that my newfound skills in R will take me far. So don’t be afraid to take this class, just don’t expect an easy ride.

To anyone considering taking this class: understand that the course in its current state is flawed. Ideally, you shouldn't have to have prior programming experience to be able to succeed in this class, but as it stands, you should consider taking PIC 10A or CS 31 before attempting this class. Hopefully Stats 20 gets changed for the better in the future, but for now you'd be doing yourself a favor by getting some programming experience first.

Stats 20 has been redesigned to be much more rigorous. People struggled a lot this quarter.
The problem was with the way the class is designed. It tests you on your knowledge of R functions and nuances, when it should be testing your ABILITY to program in R. The exams were tricky and focused on details. They should've been testing statistical programming concepts, rather than testing if we memorized things that we could just Google in the real world. The Stats department needs to look to the CS department and follow their example in how to design an introductory programming course.

I appreciate the generous curve that Mike gave out in the end, and how gracefully he handled all the criticism he received over the course of the quarter. Mike really is a good professor and very supportive of his students. It's not his fault that this class was doomed. I only hope that he is just as vocal as we are to the Stats department about finding a solution for the issues in Stats 20.

General info:
The professor's lectures were pre-recorded and he mostly just read the content in the lecture notes. He has office hours during his normal lecture time.
We had 7 homework assignments (technically 8, but the last one was optional and mostly for final prep) throughout the quarter. Each homework is graded on satisfactory completion (so even if your answer is wrong, if the grader thinks you made a good enough effort, you'll still get full points).
We had a class Campuswire where the professor and TAs were fairly active on. You get extra credit for contributing to Campuswire discussions.
Our final project was cancelled, which was nice.
Tests are very difficult and almost everyone runs out of time. There is usually one question per test that is quite niche in the sense that you probably have never seen what is described in the problem unless you spend a lot of time experimenting around with R. If you want to do well on tests, learn how to debug code quickly, since that will take up a lot of time on tests if you aren't careful.
The raw scores for the midterms were pretty low, but the professor does scale them to increase your score a little.
Some stats for midterms (from the scaled scores, not the raw scores):
Midterm 1: median = 61, mean = 62
Midterm 2: median = 65, mean = 64
I had TA Jake and I interacted with him once in week 1 and then never saw him again. I think he stopped holding discussions after the first week, and I didn't see him post any discussion recordings on CCLE either. Maybe he did post recordings and I just didn't find them, I don't know. I did watch a couple discussion recordings from the other TAs though, they seemed pretty good and they gave some nice debugging examples.
This class is said to be an introductory programming class, but I would not recommend taking this class without any coding experience. There is so much material covered in so little time. If you are new to programming, be prepared to spend 10+ hours (outside of watching lecture videos) on this class per week if you want to get a good grade.
If you are new to coding, have a genuine interest in coding, and want to foster that genuine interest, do NOT take this class as your first programming class. Go take CS 31 instead... trust me.

My experience:
I came in with about 2 years of programming experience (took AP CS in high school, took CS 31, CS 32 at UCLA) and the tests in this class were still a time crunch. Homework assignments took me anywhere between 3 to 8 hours a week, depending on the assignment and how much effort I wanted to put in.
Towards the end of the quarter, I stopped watching lectures and just read the lecture notes, which I found more useful and time efficient.
If you are new to programming or would like to understand debugging more, I would recommend going to discussion. Otherwise, it's not really worth the time.