David Aaron Rios

May 2021

Nice and funny professor, though I don't know if one could take this class without prior experience with statistics. He's very chill (maybe too chill) and I don't think anyone would have a problem with him. That being said, if the concepts are new, I'd expect outside reading in addition to his notes to learn more. He also made sure not to talk too fast. He also liked to show us his dogs via Zoom video, Zoom backgrounds, and problem questions.

Apr 2021

Professor Rios is probably the funniest teacher that I've ever had, but whether we laugh with Rios or at Rios is very unclear: - For the zoom semester at least, he was often late to his own classes, and even when on time, would teach half of the slides in chat instead of speaking. Yes, in chat; the thing you use to individually dm randos in. What does this mean? If we compared this to a regular semester, it would equate to writing out his speech on post its and taping them to students' foreheads. - His test questions were incredibly unclear. His practice exams were great and trained us well for the content, but when we got to the actual test... the final was like one big question, but it had the most cryptic questions ever. These weren't hard questions, but questions that made no sense. He also may have made a 69 joke on the final (he claimed n=69 when n=62, and then corrected himself minutes before the final was due). Maybe that's just my inner Rios talking. - He went out of his way to make pretty funny jokes. He's like a stats dad with all the dad jokes. PLUS he often featured his dogs in class. - He is super super understanding. He is very nice and genuinely feels for his students. Either that or he's way too lenient. No no, I swear he's just really nice. - He often gave one word responses to emails. My point is, Rios is VERY unprofessional for a stats teacher, but whether that's a bad thing is for you to decide. If you need to get this out of the way as a requirement, it's easy to do well while having a minimally adequate grasp of material. If you actually need to learn it, RUN; there will be a lot of self teaching, excel-ing, anova-ing, and reading the textbook-ing involved.

Jan 2021

He was chill but maybe too chill. He doesn't really teach the materials covered on the midterms properly. He took a week to respond to some emails, and he sometimes was late to zoom class. He didn't really take the class as seriously as he should have. However, he was pretty understanding of our current online situation as well.

Dec 2020

Super chill guy and like someone else mentioned I wish the class was in person so we could get to know him better. That being said I watched 10 hours of youtube videos to understand the material. So if you DO take this class here is some advice: - The class material is all over the place and the lecture notes are very difficult to follow, I often ended up having 0 ideas what was going on - with that being said what helped me was to watch youtube lectures on similar concepts covered in class and what was stated on the syllabus (e.g One-way Anova) - Whenever you see an equation in the notes, write it down and compare it to the textbook or look it up to make sure you understand the reasoning behind said equation/proof - Don't pay too much attention to actually understanding the HW's as they won't adequately prepare you for the Exams - Focus on his practice tests; they won't make perfect sense but you'll get an idea of how to answer Questions - TA Office Hours!

Dec 2020

Professor Rios is a great person and funny guy. I wish we had in person classes this semester because I feel like the connection between him and his students would have been better. But this man is a god-awful professor. We learn things in class, especially how to do certain things using Excel, and then we can't use Excel on the exam. The exam has nothing to do with the homework you're assigned, what's taught in class, and what you do on the practice exam.. so good luck. If you want to actually learn statistics, take a different course or teach it to yourself. If you want a good grade, try your luck at this course because the only thing good about it is the curve. This course would have been good if what was taught in class, what showed up on the HW, what was used on the practice exams, and what showed up on the actual exam all correlated. Unfortunately it didn't so you're stuck guessing what could possibly show up on the exam and if the curve will allow you to pass the course. I feel like I should understand the basic statistical concepts better than I do right now after sitting in this class for an entire semester but I don't. I'm nervous to take upper level Statistics classes after this one because now I don't have a solid background.

Sep 2020

I took Probability Theory with David Rios. Unlike his intro stats class, I thought he was a damn good teacher for Probability Theory. His slides were clear and he explained the material thoroughly. His Office Hours were great. It's a hard class, but that's content not teaching. Overall, his teaching for the course was a little below-average for Columbia professors but that's normal. My personal suspicion is that he is totally plastered in the intro stats classes. I noticed they appear to be on his off days and he always came in a total wreck. In the intro stats course lectures, he swayed side to side a lot, really seemed out of it, said hilarious nonsense, and was unintelligible. Probability Theory was the opposite. Most lectures Rios was wearing a suit, was totally lucid and knew his stuff. I suspect he just doesn't care about the introductory classes.

May 2020

Professor Rios is a very chill professor. He is very approachable. But he did not take the class he taught as seriously as he should. He usually responds to 1 out of 5 emails you sent. He only will teach the very basic concepts during lectures (information you can get from watching youtube videos anyway). He would not bother working on hard problems with students in detail. To be honest, it is a misfortune that some Columbia students have to pay such high tuition and are required to spend their money on a class like this. In summary, I think Professor Rios is a nice person, but far from a good professor. (This statement stays true for a lot of the professors at Columbia.)

Dec 2019

I took Professor Rios' STAT4207 (typically taught by Mark Brown) this semester. Reading the other reviews, I was actually quite scared to take his class. However, I had quite a positive experience. He is incredibly approachable, always happy to answer questions during and post-lecture and also in OH, and provide intuition behind the complex math, as well as insight regarding real-world applications in finance/trading. He often said things like: "never be sorry for asking a question" to encourage people to speak up and ask for clarifications. Moreover, the book was often not very easy to follow (examples quickly spiral out of control), but his notes, which he also posted on courseworks, emphasized the concepts that we needed to know for both the assignments and the exams. Though he started every class with a "roadmap" (i.e. what we intend to accomplish during the class, and what we can expect to do in the following class), the class could definitely use a bit more structure, especially when it comes to notifying students of exam scope early enough in advance. Nevertheless, Professor Rios is open to feedback and clearly incorporated students' feedback in shaping the class later on in the semester. TLDR; As the previous review suggests, Professor Rios is clearly improving. He is approachable, responsive, open to feedback, and very capable of explaining complex concepts in very simple language. Would recommend taking a class with him.

May 2019

The other reviews are not correct. David Rios is not the most inspiring professor, but his lectures get the job done, he is very approachable, he is constantly on Piazza, and the homeworks are very helpful. The TAs were helpful as well. Sometimes, Rios even brings his dog to lecture!

Dec 2018

As all other reviews have mentioned, Rios is a terrible professor. However, I would still recommend the class if all you are interested in is getting an easy A. First of all, you don't have to go to lecture. In fact, you shouldn't waste yout time doing so. Instead, learn the material from the textbook, which I guarantee will take less time, and should be enough to do the Psets. Most questions in the Psets are taken directly from the textbook, so it shouldn't be hard to find the answers regardless. Secondly, the exams are identical to the practice ones he posts beforehand. He'll change the numbers, but the problems are the same, so you can just memorize them beforehand. Finally, he curves the class a ton. I believe he does it so that it is 50% A, 40% B and 10% all others, but I'm entirely sure. In any case, the average on the exams was usually around 55-60, so anything beyond that should guarantee an A. Overall, Rios' class is a good option if you are willing to do all the work by yourself and have a good chance of getting an A. I'd particularly recommend it if you've done stats before, as that certainly helped me.

Dec 2018

David Rios possibly has many strengths, none of which include clarity or teaching style. He was tardy to class, dismissed us early, and had dry lectures that were impossible to stay engaged with. His notes make little sense, as he jumps from shortcut to shortcut--he almost seems to take pleasure in being roundabout and offering no real explanations. His problem sets were not as challenging as they were absolutely impossible to decipher the questions he was asking. Rios is obviously smart and has talents, but these are far outside the realm of teaching.

Apr 2018

Rios is a terrible professor, probably the worst I've had at Columbia. His lectures are incoherent and confusing, often teaching material differently from the textbook and spending most of the class writing on the board rather than teaching anything. The problem sets are a similar story- very confusing and often unrelated to in-class examples. The problem sets are usually due before the necessary material has been taught, so he usually ends up giving extensions every week. The class itself, however, is quite easy. As long as you study from the textbook, the midterms should be easy and Rios curves the class a lot (I believe a 50% A range). I would therefore recommend the class if you have prior experience in stats and/or if you don't mind learning all the material from the textbook. Avoid this class if this is your first experience with stats.

Feb 2018

Cannot soell trials - spells it as trails

Nov 2017

Would not advise. Rios is not very good at explaining concepts. He seems to be very smart, but his teaching skills are just not there. He will work through complex problems in his head, skip steps, estimate numbers "to make it easier for him," and his handwriting is horrendous. The class follows no particular order and he says that the book is useless even though his syllabus says you won't succeed unless you use the book... Overall, a very unsatisfactory experience. The only issue is, it seems that all the professors in the Stats department here at Columbia are just as bad based on other reviews. I have yet to find a teacher that has more than 5 reviews stating that they're "good." For anyone wishing to take statistics, search for Professor Leonard on youtube. He has a robust channel that covers all of the concepts and he is amazing at explaining them. This is the only reason why I did not fail miserably in class.

Dec 2016

I immediately dropped his class within the shop period. I had hoped that his Introduction to Statistics without Calculus wouldn't be complicated, but I was wrong. His lessons were incredibly rushed. His homework almost seemed unrelated and too much in comparison to what we had accomplished during the shop period. He made us use excel (which I usually have no objections to) but did not teach us or tell us how to use certain functions necessary. Any questions that were asked were not answered well and he seemed condescending about us not knowing the material well. He told us we didn't really even need the textbook and that we could technically use any statistics textbook. He only had 1 TA with very limited office hours. In summary, his class was unorganized and he gave off the feeling that he did not plan ahead too much.

Nov 2016

DO NOT TAKE THIS COURSE! Rios is the most disorganized and confusing lecturer and showing up to class often feels fruitless since you feel more confused on the course material after a lecture than before it. There are weekly homework assignments and though they aren't typically too long, they often make no sense and I've spent hours in the statistics help room trying to decipher what he means. Half of the class dropped it by the first midterm.