Fall 2020 - Prof. Willis is a fantastic lecturer; he's really responsive during lectures and actually pays attention to the questions asked in the chat (he'll actually answer all of them and make sure you understand by demonstrating with examples). His pacing during lectures is pretty much perfect, and the concepts were explained super clearly. He's also pretty funny and will interact with the students in the chat. Workload for this class is decent, there's a few written homework problems paired with online Sapling homework due every week. If there were any homework problems students were stuck on, Prof. Willis and the TAs would be super helpful during their office hours. The midterms and final were open-note, 24-hour window assignment-like exams submitted through Gradescope. The lectures were recorded, and attendance wasn't required for either the lectures or discussions. (Michael Johnson was also a pretty awesome TA; he was super helpful.)
Winter 2019 - Michael Willis is a mad genius. His style of teaching is very unorthodox, so it might/might not work for everyone, but I loved it and I felt very comfortable with the material. Linear algebra isn't as easy of a subject as everyone believes because of how abstract some of the material can be, but Willis makes it work with his very casual and informal way of explaining the concepts. He makes reasonable tests and is overall a nice guy who initially comes off as a little abrasive but is actually just really eccentric and really funny. Willis made me truly interested in the material and I recommend to anyone taking this class.
Fall 2018 - Man. I'm writing this some time after the class and the C still hurts today. Willis is bar-none the best lecturer for math at UCLA. He explains things organically--it's like having a good friend of yours teach you a subject. He's very chill, but puts effort into his teaching. He chooses his words carefully to avoid the least confusion possible. He uses casual speech, writes clearly, etc. This sounds mean, but he's the only professor I've had for math that is a native English speaker... moreover, he's not some old dude that puts professionalism first. Willis cares about one thing: teach in a way that makes sense. And it works. You'll notice that the shittier professors try to seem very formal, cold, by-the-book, etc. The best ones throw caution to the wind and just *teach.* Willis is the latter--attend lectures and focus more on listening and watching than taking notes. If you NEED to take notes, I honestly say use the book for that. I truly felt like I had learned differential equations fairly well in the class... so why a C? Simple answer is, I missed one problem on one midterm. The biggest criticism I have is that the tests are too easy! So easy, in fact, that missing a single problem on a test will literally get you a C in the class. I scored a bit above average on the final and exactly average on the 1st midterm. The 2nd midterm, however, had 4 problems. I did OK on the other 3 (again, did average), but one problem I made a stupid assumption... which got me a 0/10 where everyone else got 10/10 on that problem. I made a "duh" mistake, kinda misread the problem statement. On a test where the average is >90%, that immediately earned me a C on the test. Throw in a couple of -1 or -2 points on the other problems... that one problem got me a D on that test. So the easy tests are a double-edged sword... would you rather your final be 3 multiple choice questions or a holistic, long-form exam composed for 4 or 5 long questions? Miss one MC problem and you get a D. In the end, it was my own fault which is why I still recommend Willis. Just look out for his easy tests and know that the averages will be very high.
Spring 2020 - I thought the course material was fairly straightforward, and Prof. Willis certainly helps make it even more so. He's a clear lecturer and he's always willing to take questions during lecture, help out during office hours, and take suggestions from students about the course structure, which was key since Spring 2020 was remote/online. The overall grade is: weekly homework (20%), two midterms (20% each), and the final (40%). Exams were fair, possibly even more so than the homework assignments, each of which always seemed to have one really tough problem. In general, I'd definitely recommend taking 120A with Willis.