professor


Dec 2020 
Explains group theory without a textbook in his own concise narrative. Lots of guidance written into difficult exercises on homework. His own typedup notes are thorough and provided at the end of lectures that go over the material covered in the lectures. Overall, an excellent course on introductory group theory.
Dec 2020 
As previous reviews have stated, Prof. Friedman is not human. His lectures move at a breakneck pace, and there's no way a mere mortal would be able to write so quickly; surely their forearms would cramp. The online semester actually saved me here, since I could go back and rewatch lectures at .75x, which still required pausing to write everything down. He is a good and incredibly thorough teacher; you'll never need to ask him to go deeper. There is a problem set due on EVERY Monday, regardless of exams or holidays, for a total of 14. These are long and difficult, but do enhance your understanding of the material and are sufficient preparation for exams. I didn't think the exams (2 midterms and a final) were particularly difficult if you did the homework honestly. Prof. Friedman does not use a textbook and instead typesets his own notes, which he uploads after most lectures. They are beautiful and incredibly thorough, and reading through them makes you question whether he is a human or a publishing company. I want to emphasize the pace of the class again. It was not forgiving, and he didn't even afford us the liberty of dropping the lowest homework. Gods like Prof. Friedman do not need to drop homework since they never have a rough week, but we mortals do. All in all, I did pretty well in the class, but I was decently traumatized.
Dec 2020 
This class was taxing. Is Friedman a great professor? Sure, he teaches the concepts well. However, as an earlier review said, he speaks faster than the disclaimers at the end of medicine commercials! In the words of a fellow student "Friedman's lectures are like drinking out of a firehose." Are you hydrated? Sure, have you also been drowned? Also yes. I feel like I learned a lot but he made the class over the top rigorous. The problem sets took years off my life. They were significantly harder than what you would expect from an intro to group theory class. As for his exams: the two midterms and the final exam were very fair but also incredibly difficult. Like the kind of exams where you recognize everything and then suddenly you're on part 7 of a question and you're entirely lost on how to finish it. I found the final to be extraordinarily difficult but that was because I was so exhausted by his class that I had no energy left to try. TLDR: Friedman is a nice guy, the class is like drinking from a fire hose, and above all this class reminded me to take my psychiatric medication every day :)
Sep 2020 
I did not like his class. Prof. Friedman would focus on proofs and I found that the actual formulas and theorems often got lost in the complicated proof notes. Homework wasn't too hard, nor were the midterms or final. His review sessions were sometimes helpful. I was pretty upset about coming into office hours once and Prof. Friedman seemed annoyed when I introduced myself (sorry?) and when I explained to him the struggle I was having understanding a problem he acted like he had no idea what I was talking about which wasn't very helpful.
Dec 2019 
This was my first purelecture class and it definitely took a bit to get used to. Robert Friedman is very passionate about math, and he covered an extremely extensive amount of content over the semester. It was initially a bit difficult to adjust to his fastpaced teaching style, but I came to appreciate it. he covered more than just the "basics" and made sure that we understood exactly how everything worked, often explaining how the formulas worked in multiple contexts. His geometric representations were helpful, and despite it being impossible to take notes on absolutely everything in the class, it was definitely worth the attempt, because I learned so much, and I feel like he has taught multivariable calculus wonderfully. I, unfortunately, was unable to attend office hours because of a schedule conflict, but the preexam review sessions were very helpful, and any time I talked to him outside of class he was extremely nice. Whenever you asked him a question, he wanted to make sure that you understood the answer, and even though sometimes there wasn't time for him to answer questions in appropriate depth in class, he definitely wants to help you out if you ask for it (though each class seems like its meticulously planned out, so you might want to keep questions during class brief). I had a bit of an issue with the difficulty of the homework; it often was much more challenging than what we did in class, and it felt like it relied more on trying to trick you than the exams, which were straightforward. Inclass examples were about the level of the exams but didn't always help with the homework. As someone who hadn't taken Multi before, the class felt a bit intimidating at times when I'm pretty sure nearly everyone in there had, and my grade is probably going to reflect that (the midterms don't seem to be curved, and I believe the class average for the first was a 93% and for the second an 86%), so we'll see how the final goes. Overall, I do appreciate the professor, and though I think the class might have been a bit denser than it could have, I recommend it.
Dec 2019 
Super smart guy and great teacher. Pretty funny too. Operates more like a detailoriented, handholding highschool teacher than the infamous caricature of the disorganized, selfabsorbed college professor. He really cares whether you understand or not, encourages you to see him and the TAs anytime, and holds Sunday evening review sessions before every exam. He could be the department's greatest teacher, but he will spend increasing amounts of class time as the semester passes deriving the results, instead of applying them as you have to do on the HW and exams. Interesting but misleading and rather tedious, though the abundance of chemists and physicists in the class seemed to love it. Average kiddos (like yours truly) tend to be quiet, bored, and/or too shy to speak up. I got an A in multi my senior year of high school and I think I'm getting an A in this class. His exams aren't that hard; it's the homework that screwed me over. He assigns even problems only and the TAs grade mercilessly for accuracy. I didn't discover Slader until the last two assignments of the semester and my earlier homework grades fluctuated between 80%90%. Lots of my classmates definitely got >95% on every assignment. Just pay more attention in class, care more about your psets, and check your answers with Slader. An A is extremely doable :)
May 2018 
This course was altogether uninspiring. I guess I learned how to represent finite groups. But I did not come away with a clear concept of why. There were no motivations or applications. Lecture is ok. Friedman has horrid handwriting, but it is possible to follow what he is saying. However, he gives out very thorough lecture notes afterwards, so it is much more effective to skip class and read the notes! The homework assignments were long and tedious. There were a ton of computations. The exams repeated a ton of material from the homework and required a great deal of memorization. Overall, the course is simply not worth it. You spend all semester doing computations and memorizing definitions, with no payoff. Not to mention that the course is curved downward, so you have to get practically everything correct to get an A.
May 2016 
I couldn't imagine a more straight forward class. Or a more clear professor. Friedman adheres to Chekhov's Gun Principle in all his lectures. He'll mention some tidbit at the beginning; you won't understand it. An hour will pass. You will have scribbled five pages of notes that seem to have no connection from one line to the next. Then with five minutes left, he fires Chekhov's gun, weaves the lecture right back to the tidbit he dropped in the first five minutes. And your newlyconnected synapses will high five each other. You will realize pure math is beautiful. The best part of this course was stepping into deeper levels of abstraction week to week. Take quotient groups for example. You start with (Z/nZ) in an isolated case; you learn some rules for (Z/nZ), learn some proofs, and think that's it. Then three weeks later you learn about cosets and quotient groups and realize (Z/nZ) is just one instance of a quotient group. Sure, he could teach about general quotient groups then give Z/nZ as an example. But it's so much cooler to step back from your one example and have all the theorems make sense a month later. Chekhov's gun, people. He types up a great sheet of notes so about half the class skips lecture. Don't do this. He won the Van Doren teaching award for a reason; spending three hours per week in his class is worth it. I devoted every Sunday to the problem sets. The entire Sunday. Then I'd take any questions I had to the TA help room Monday morning; the TA from Taiwan is really great, though I can't remember his name. The problem sets are graded pretty harshly; expect points of unless you're perfect, another reason to go to office hours. I changed my major from CS to math because of this class. I'm taking his Algebra II course next semester as well because he is stellar. Take anything he offers.
May 2015 
Friedman is a polarizing guy just look at the allornothing reviews below this one. Yet, I'm pretty split on him. If Friedman is (in)famous for anything, it's for talking faster than the disclaimers at the end of a medicine commercial. While this isn't untrue, he doesn't actually move through material as quickly as one would expect by counting his wordsperminute, instead drawing out the obvious and writing out every detail to the extent that his proofs are nearly computercheckable. This isn't entirely bad, especially if modern algebra is your first real proofbased class, but it makes the class appear to move a lot faster than it does and there were some topics we didn't have time to do. For instance, we did very little with symmetries of geometric solids, which is traditionally an important application of group theory. The bright side is that Friedman is pretty devoted to this class. He wrote up solutions for the problem sets, posted review sheets, and held review sessions all to help us prepare for exams. I think he even knows my name but I haven't found a way to test this theory. The exams themselves are all straightforward. He sometimes takes ideas from the homeworks, so doing them is advisable just in case you were on the fence.
May 2014 
Robert Friedman does all you can ask of him. I don't know why he has some stigma of being a terrible professor. Calc IV can be hard at times (I took Multi in high school and still struggled) and some people just want to put it on him. He tries his best to teach you the material so he does challenge you, but at the same time he spends a lot of time trying to make sure you'll do well in the class. It's true the curve it's minimal, but he makes the test easy (but some times tricky) enough for everyone to do well so there really is no statistical reason to add one. I think your final grade may be curved a bit. I had about an 87% and that became an A. Just take a good amount of time before each exam to really break the course down into Layman's terms and list steps on how to solve the problems and you'll do fine. He does so many things to let you know he actually cares.
Jan 2013 
Professor Friedman is absolutely brilliant. So brilliant, that he lectures at an insane pace because he assumes that everyone knows exactly what he's talking about. Which is probably about right. The lecture speed takes a little time to getting used to, but maybe that's because he has so much material to cover in a semester. He mentioned at the beginning of the semester, if you want to slow him down, ask questions. The bane of this class is the problem sets. The problem sets are tremendously long and difficult, and if you leave it to the last day to finish, I can guarantee you will be emailing him about an extension. Definitely work in groups, and make use of the TA's office hours and the math help room. The problem sets are incredible though when you figure them out, and they contribute greatly to your understanding of the material. I cannot stress this enough. Some of the examination questions are based off material found in the homeworks. It's very crucial to study each problem closely before each midterm. Know your vocabulary. To the letter. The vocabulary is a huge foundation of the material and he begins every examination with definitions. Memorizing definitions goes a long way to helping you cope with the difficulty of this class. Friedman is very receptive during office hours and although it may be a tad intimidating speaking to him oneonone because of his brilliance, he's very helpful and interested in each student. He is a fantastic professor, and if you are willing to put in the time and effort, you will come out with a greater understanding of algebra. If you're a genius at math you will probably find little to no issues with this class. But if you're like me and you're not gifted at math, then prepare to put in long hours into this class.
Apr 2012 
Many men, mere mortals, have wondered whether Robert Friedman is human, divine, or something else, something more. While we may never know, it hardly matters. Do not â€“ I repeat, do not â€“ miss the opportunity to let this man's radiant brilliance shine forth upon you. Much like, having fallen into the ocean, it is impossible to emerge dry, it is impossible for you not to have become a substantively better human being in every possible respect upon leaving Friedman's classroom after your final exam. Not only will you be an incredible mathematician who will probably solve the 6 remaining Millenium Problems (Friedman already has, he just has no interest in publishing the solutions since he uses them on his problem sets), but you will have the strength of a wild ox, the speed of a cheetah, and will never need to sleep again. I should mention that I told a small lie. You and I can't emerge from the ocean dry. Friedman can.
May 2011 
Professor Friedman is awesome. Having had absolutely no background in higher math, and a lot less experience than some of the class, I still truly enjoyed both semesters. That said, I'm not one to be demoralized by seemingly impossible problem sets, or less than fantastic grades, and didn't ever find that either of those things interfered with my enjoyment of the class. For those who aren't this way, be wary, but if you are willing to put in the work, you will come out of Friedman's class with a tremendous improvement and a truly deep understanding of what you've learned. Though all of my classmates that I've talked to have varying opinions on the class itself, we all agreed on that. Often Friedman wont answer questions immediately because he carefully plans out the structure of his classes, and likes to stick to this. This never bothered me because his lesson plan is brilliant and incredibly well thought out. I also really liked his teaching style and thought he was very clear, but it may take some getting used to. He wrote our class notes, which totaled a few hundred pages, himself. The problem sets are difficult, and existentialcrisisinducing if you decide to start them 12 hours before they are due. However, they are meant to be done in groups, and they often took my friends and I even longer to finish because they inspired conversations that gave us a deeper understanding of the material. Ultimately, I loved this class and was so glad I took it. Friedman is fantastic, and though the class is incredibly challenging, it is completely worth it.
May 2011 
If you've done hardcore math before, the previous two reviews will probably apply to you. Otherwise, they really won't. I hope that this one somewhat applies to the rest of us. Granted, even after going through this class, I'm still math majoring, so take my review with a grain of salt. I like to think I'm somewhere in between the (substantial number of) Honors Math A/B dropouts, and the ridiculous kids who didn't come to class yet never missed a point on anything. CLASS: In terms of content, the class covers linear algebra and calc III  IV from a proofbased perspective. It also gave students an idea of what's to come, should they start taking upperlevel mathematics courses... so definitely not the standard calcIIIIV curriculum. The two biggest additions are proofs (of course there are proofs in the calc sequence, but here they're covered more rigorously, and mostly everything is proven), and adding in ndimensions, which makes things abstract and nonvisualisable. Personally, I thought the smaller asides (usually irrelevant to the course's express topics) were very interesting, once I figured out what the hell they meant. The class is also supposed to help new freshmen think in the "language" of higher math. This includes the (sometimesabsurd) notation and thinking in terms of theory, proofs, and ndimensions  rather than just pictures and examples (not that these aren't helpful, because they really are). "Help" is a subjective term, though. I don't know if it' the course's intention or it was just Friedman but I felt like this class (especially first semester) was a "baptism by fire" into higher math. To give the analogy one of my classmates called out in lecture one day: we the students, were like helpless babies thrown into the woods, at the mercy of the wolves, and expected to figure out how to survive. I thought I was good at math. So did everyone else who signed up, I'm sure. Not everyone left feeling that way. The first semester was linear algebra. we went through the topic in a very proof/theory based. Very abstract. Friedman started with linear algebra. The second semester, calculus (with some topology, differential geometry, etc. sprinkled in for good measure) was more computational and less theoretical... again, I don't know if that was Friedman's doing, or just how the course works. First semester had probably 7080 kids... on the first day of second semester, though, it was as if half of the class had discovered how to shift into dimension n, n>3 (they disappeared) PROFESSOR: Friedman is, well, one of a kind. It's hard to separate the course from him, because he really defined it and made it harder than in years prior, at least from what I hear. He mumbles at times. He sometimes physically (and maybe metaphorically) stands in front of what he's writing/talking about. In class, he chugs through proofs nonstop like the little engine that could. These things are all negatives in a class where a good portion are freshmen who haven't done higher math before. I'm sure any mathematician, or even any math major in the Help Room, could easily transform Friedman's chickenscratch into concrete calculation. It wasn't that easy for me (and a lot of other kids in the class). Oh, and his handwriting/drawings suck. I thought that he really improved in the second semester, though. He started giving more examples, rather than just the proof/theory behind concrete concepts important for those of us with no previous exposure. I felt that he just generally explained the material more clearly. Class became actually helpful, not just an attempt to set the Guinness World Record for most proofs written in an hour (I use these absurd analogies because I thought the first semester was kind of absurd). Still, if you miss a beat (whether because you space out, or because you don't get how something logically follows in a proof, or anything), you're probably going to be lost for the rest of lecture. In office hours/review sessions, he was totally different. Very helpful and took his time in explaining the concepts. Unfortunately, his review sessions were like therapy sessions: he allotted exactly an hour to this session, and we got exactly an hour  no more, even if lots of people still had questions. Similarly, he himself was only available about four hours a week, and the TAs had 1 office hour between them (in the Math Help Room). Then again, pretty much anyone in the Math Help Room can help you with problems you're having, so it's not the worst thing in the world.
Apr 2011 
I liked the class. Friedman knows his stuff and the course is well thought out, though he doesn't follow the "texts" at all, they're more like supplementary reading. His notes basically cover his lectures and are pretty complete and intuitive. I do agree that the notation is a bit confusing at times, but that can be easily clarified by just asking him or the TA what's up with it. The course is curved, but very little, no big deal. Just go to class, ask questions (not during class, friedman's got lotsa stuff to cover...), start your homework before Monday morning when it's due. It's not an easy course but being a good student should be enough for you to do well... On a side note, the guy does actually have a sense of humor and is pretty friendly.
Apr 2011 
Prof. Friedman is a pretty cool guy. He occasionally writes too faintly on the blackboard or goes off on tangents, but those tangents are always fascinating and will give you a greater appreciation of the subject. If you snooze in his class, that's okay too, he doesn't judge. He posts class notes online, and they're super helpful when you're studying for exams or just going over material to complete the homework. (Only thing is that he writes really fast sometimes, so it might be a good idea to bring a copy of the current chapter in the notes to class and follow along.) Class isn't ever stuffy or boring. He makes a fair number of (slightly lame, but endearing) jokes to lighten it up. His lectures are always really wellprepared and at a good level of difficulty. He'll usually review the hardest part of the previous lecture at the beginning of class, so come to class on time. If you ask him a question or go to office hours, he's always really eager to help and answer your question as fully as possible. I found the course itself (Honors Math A/B) incredibly enlightening. In addition to basic linear algebra/multivariable calculus stuff, it introduces you to a whole host of theoretical math topics that give you a taste of "higher math." Some of it relates to physics, and I found that seeing the same material twice, from different points of view, helped me understand it better. This course is a definite musttake if you're considering majoring in mathematics.
Jan 2011 
To begin with, I recommend that you avoid taking this class with Friedman if at all possible. I realize that this is the math class for freshmen math majors and more often than not you will not be able to avoid it and this fact only makes all the more terrible that they assigned Friedman to teach it. We spent most of the semester on Linear Algebra and the last 2 weeks or so on properties of real numbers. All the calculus is presumably covered in Honors Math B. The biggest issues with this class are as follows: 1. You spend hours and hours doing difficult problem sets every weekend. They were assigned on Wednesday nights and due on Mondays. Obviously no one got a chance to look at them till the weekend and hence there was practically no help for the homeworks other than a Friday morning recitation which no one went to because no one started the homework till Friday evening. His office hours, being on Tuesdays(?) and Thursdays are pretty much useless for getting homework help. If you try to write halfassed proofs, you will lose lots of points and do badly in the class so you pretty much have waste your whole weekend on this class. 2. THERE IS NO TEXTBOOK FOR THIS CLASS. Friedman assigned a textbook because he was obliged to but never referred to or suggested it in class. I tried reading it for a few weeks but it was too advanced and of little help in solving the homeworks. Instead Friedman uploads his own typed notes but they are very confusing, the notation is bewildering and completely unintuitive to a student with little higher math background. As for the lectures, he goes really fast and writes really fast. Most of the time what he said went completely over my head and his handwriting and presentation on the board is abysmal. Basically you either try to take notes or just listen. I would recommend listening, you might absorb something. The notes will just be a somewhat extended version of what he posts online. Going to lecture is probably a good idea just so that you can have a vague idea of what topics/ideas were taught as there is no textbook to refer to. He did not show up to office hours the day before the final and did not send out an email or tell anyone that he wouldn't be there. Everyone who went just waited for 20 minutes and then went home. You would think that the professor who show up to office the day before the final exam but I guess not which just makes me think that he really didn't give a damn about teaching the class.
Jan 2011 
CULPA warned me not to take Friedman's class, but I did anyway, because, unfortunately, he was the only teacher for Honors Math A. I can't say that I'm sorry I took Friedman's class simply because Honors Math A was definitely the right choice for me since I had already completed the calculus sequence in high school, but IF YOU HAVE ANY CHOICE IN THE MATTER, AVOID FRIEDMAN LIKE THE PLAGUE! If you are on the fence about taking Honors Math A anyway, and Friedman is the only teacher, then I would say don't take it. The material in the course is extremely fascinating, but it is abstract, and Friedman is incapable of stringing together a coherent sentence, taking notes in an organized or legible fashion, and answering students' questions. On the first day, he told us that if we did not understand something, we should ask, but he never answered a single question for the entire semester. He usually just ignored raised hands, but when he did call on someone, he would either say, in irritation, I already covered that, I'm not explaining it again, or, We're not up to that yet, I'm not explaining it yet. I stopped going to class after Thanksgiving break, and it in no way interfered with my understanding of the material or my grades in the classthis should give you some idea of how useless the lectures were. The recitations were equally useless. I went to one and it was just the TA repeating what Friedman had saidonly it was slightly worse, because Friedman didn't bother to tell the TA what he was teaching, so a lot of the stuff was completely irrelevant. Furthermore, at least Friedman is brilliant and has a deep understanding of the material he is teaching, even if he doesn't know how to teach, and doesn't much care either; it was obvious that the TAs barely had a handle on the information they were presenting. The grading is something of a nightmare. Two TAs take turns grading the problem sets. They just do whatever they want and Friedman does not interfere. One TA refused to give above a 70/80 no matter what while the other always gave me about a 70/80, even though my problem sets were all about equally correct. Every student in the class had a similar experience. Furthermore, the "nice" TA then decided to grade out of 40 while the "evil" TA graded out of 80...Friedman failed to realize that when taking an average, this meant the "evil" TAs homeworks counted for twice the "nice" TAs homeworks. Comments on the homeworks were minimal and useless in terms of understanding how to improve. Only a few problems a week were graded so you ended up feeling like you wasted a lot of time AND it was just luck whether that one problem you didn't fully understand counted for a third of the homework. Friedman himself graded the midterm, which was surprisingly easy, yet no body did as well as they expected to/should have. Why? I never thought it was possible in math until this class, but Friedman's grading was extremely SUBJECTIVE. That said, I got an A, thanks to the curve, and I think most people got As or Bs. The lowdown? If you love math, have a strong background in math, are good at math and a creative thinker, and are willing to put in the time to teach yourself the material in addition to doing the absolutely endless (albeit interesting if you understand what's going onsee Workload) problem sets, and there is no other teacher teaching the course, then suffer through it for your love of math and the material, knowing that it's basically like getting credit for teaching the course to yourself. The one useful thing Friedman does is post a textbook of course notes he wrote himself online. While not ideal, they are infinitely better than his lecture notes, and I used them to teach myself, and I do think I learned a lot. He never uses or refers to the textbook you have to buy. I looked at it once and it just confused me because it uses different notation and terms than Friedman.
Dec 2010 
Initially, people may find Friedman to be intimidating and unapproachable, but he really is not. He is a wonderful and knowledgeable professor who actually knows how to teach PROPERLY and communicate to students the necessary mathematical intuition. Limited memorization needed if you can follow the lectures (fast, but decent pace, and enough examples to show how to compute the things). Those who have an issue with his handwriting are exaggerating; it is more than readable if you understand what's going on. The proofs that are presented, which the majority of the class hates, are actually necessary to understanding the material. The topics get progressively cooler and more interesting to all who actually care about any type of mathematics, especially when you get to vector fields; although it does get difficult, I got the feeling that Friedman explained Stokes and Divergence Theorem very well that I can now apply it to physics, among other fields. Ultimately, he tied everything together so beautifully by concluding the semester with a discussion about complex numbers, of which his notes are really helpful and can replace any textbook (they still serve me well in higher level applied math courses). Conclusion on the prof: A+ effort and ability. Very willing to help and generally open to "intelligent" comments/ ques. (most of the questions being asked were just plain stupid that even I cannot tolerate them!!!  no wonder he dismissed them) Grading and Workload: Quizzes (10%)  time can be a little short if you don't know the material cold, but are very helpful preps for the exams. Manageable if you reviewed at all beforehand. Lowest one dropped. Around 14 Problem Sets (10%)  well chosen problems, with a good mix of proofs and applications/computations, and quite easily done in an hour Two Midterms (25% each), Cumulative Final (30%)  NO proofs; straightforward and almost a replica of the practice exams. Try to work quickly and leave time to check your work, though silly mistakes aren't penalized a lot. No curve; you won't need one since you'll come out with such an "unbelievable" understanding of the material due to Friedman's clear explanations that doing well isn't an issue. Enjoyable, and possibly best, experience thus far at Columbia.
May 2010 
It's funny how Friedman has a bunch of positive reviews, then about 5 recent negative ones from the debacle that was Spring 2010 Calc IV. At the beginning of that class, he said something along the lines of "Many of you are probably here because you read all those positive CULPA reviews. Let me tell you, they are not at all accurate. I have messy handwriting, go too fast, and am often incomprehensible." He was totally right.
May 2010 
Professor Friedman's Calc IV class was probably the hardest math class I've ever taken. His handwriting, true to past reviews, is horrible (although he does acknowledge the fact on the very first day of class). Part of reason it's so horrible may be the fact that he writes so fast that students can hardly catch up. Make sure to ask him what he wrote if you can't read it he won't mind. Also, since he usually writes down a bunch of proofs, which are really helpful to understanding the material (and one should write down), one shouldn't worry too much if something is missed because the proofs ultimately are not on the exams. The main point is that Friedman really knows his stuff. He has the ability to answer just about any question you have on the material. Yes, he might be kind of a prick during class when it comes to answering excessively nitpicky questions, but if you visit him during office hours, he is actually extremely helpful. I don't think he's nearly as arrogant as some of the past reviewers make him out to be. Concerning his practice exams, they are almost EXACTLY like his exams. Like the past reviewer said, there might be a slight difference in perhaps parametrizing a paraboloid instead of a sphere, but ultimately, oneâ€™s performance on the practice exam and oneâ€™s performance on the actual exam are highly correlated. The homework problem sets generally arenâ€™t too bad, except for a few near the end with the complex functions find some study buddies in the class! Inclass quizzes are pretty much counted for nothing, and the basic gist of them is to give you an idea of what you should know for the exams. The fact of the matter is, material in Calc IV just sucks to learn, no matter who the professor is. I think Friedman is getting a lot of crap for not necessarily being a lousy professor, but for teaching a lousy subject.
May 2010 
I don't understand why people are complaining about Robert Friedman. Although I took this class last spring (09), I just had to say something here. Perhaps those who are complaining are simply the ones not willing to put in the time and effort to succeed in this class, which frankly, is not a very difficult thing to do. All you have to do make sure you understand the homework, because the exams will never be harder than the homework. As for his arrogance, I don't know what people are complaining about. He was nice enough to post a practice final when I asked him. He also gave me my midterm outside the classroom when I went to get some water, which was surprising since I hadn't even talked to him before. And he was very helpful during office hours. Yes, his handwriting sucks, and he writes fast, but grow up. I've seen worse. If you're looking for an easy A, this class probably isn't it. I only said probably, because it is an easy A for some of us. (Hint: I'm an applied math major.) If you want to see a hard class to cry about, go take PDE, Stochastic Models, or Numerical Methods. I apologize if that was a bit of a rant, but I'm sick of seeing people whine about Friedman or Calculus IV.
May 2010 
Friedman is fine. The other reviewers below are crazy. Yes, he moves through the material quickly, and yes, if you ask a question in lecture that indicates you have no idea what the hell he's talking about, he'll gently blow you off rather than waste 20 minutes going back to the beginning. But he sticks to the schedule like clockwork and is incredibly available "OH are xx:xx to yy:yy or feel free to just drop by anytime" and will go as slow as you need in OH. He also added a weekly TA recitation this semester that was held 1 hour before class on the day the homework was due, which was great for getting help on that one problem you couldn't figure out or that one example in the book that doesn't make sense. Yes, he gives practice exams, and yes, they are the exact same format as the tests they're practice for. No, the problems aren't exactly the same, and yes, you might have to parameterize a paraboloid on the test when you only had to deal with a sphere on the practice test. Expecting the practice and real tests to be identical is ridiculous. Make no mistake, this is a hard class. Not only do you have to memorize a fair number of theorems, formulas and methods, you also have to develop an intuition for thinking about and parameterizing 3dimensional regions. And well, this is math, you're really only going to get so much out of lecture. Overall, this is a hard class. However, Friedman cares and makes every effort to make himself available to help you to succeed. He doesn't, however, hold your hand. (The TA might though).
May 2010 
I agree with most previous reviews: Friedman is a horrible teacher, both his teaching style and personality. I disagree with most previous reviews: Friedman is not smart at all. If youâ€™re in his class, God pities you, be prepared to self study the subject the whole entire semester. He doesn't seem to know his stuff at all. There is no point in going to his lectures because he just mumbles incoherently into the board and it is better for you to stumble through the HW problems. Worst of all, his exams were far harder than the material he attempted to teach in class, and his practice exams were nowhere near similar to the real exams. Be careful, he grades very harsh! I would never recommend Prof. Friedman as a professor, not in a billion years. No one deserves that sort of misery. To summarize, in order to do well in his terrible class you need to do three things: 1) Do the HW, skip classes 2) Memorize the practice midterms/finals 3) Drop his class as early as you can
May 2010 
This was by far my least favorite class this semester. Perhaps, the material was more difficult than Calc III but Friedman did nothing to alleviate that fact. His handwriting was completely illegible (really is it too much to ask for?). The x's and y's looked the same as well as the u's and v's; which in math is a huge problem. Not only that, but his teaching skills were severely lacking. He moved too fast through the material, focused too much on proofs and not enough on application, and was generally unresponsive to questions. He was one of those professors that expected you to know all of the answers when clearly they hadn't taught you anything. note: The last section of material he covered was complex functions, which NONE of the other Calc IV classes were doing. It wasn't in the textbook and his notes/explanations on the topic were difficult to understand. The last three problem sets made you want to cry when you looked at them. Granted, maybe I'm being a bit too harsh because I'm not doing as well as I hoped. Let me just say that I learned everything that I did from the textbook (which really is a great source). The material was just not presented in a way that was understandable. I'm sure Friedman's a smart guy, but his teaching skills need improvement.
Apr 2010 
Don't take this class with Friedman, it will be the worst experience of your college career.He is hands down THE WORST professor I have ever had at Columbia. Not only is he rude and pompous but he can't teach.We had weekly problem sets, midterm and final that were long and harshly gradedhe is a super hard grader who curves around a C+. Not worth the anxiety in any form.The subject matter is the potential to be very fascination, but Friedman absolutely kills everything. He throws notes on the board, barely explains anything. Also, he is incredibly capable of putting anyone and everyone to sleep. He is so unhelpful during office hours, it is not even worth going. He assigns problem sets that take hours to complete and does not teach you the necessary material. The TA is amazingly helpful, and even admitted that Friedman teaches horribly. If you take his class, be prepared to work your butt off and learn absolutely nothing. Avoid this class if you can.
Mar 2010 
Professor Friedman is a terrible professor. I realize that the fact he speaks English is a plus but let me tell you the man speaks fast is often incoherent and is very disorganized on the blackboard that it is useless to come to class. If you add the 4 annoying quizzes to the list I would have loved to take it with someone else.I was warned but I ignored it.... In general the Friedman creates an environment that is hostile to asking questions. If you do ask a question the answer is blurry or "I'm not going to solve this again" or he simply looks at you funny...He doesn't post answers to the problem sets or the practice midterm why? he says he doesn't have the time....His office hours are not much better and in general he seems annoyed if you ask him a question. Calc 4 is not too bad the first part (up to the first midterm is totally doable without a lot of work and the second part is harder). I think that Friedman adds the complex section more intensely then other sections and that part he just flies through.....it was hard to keep up with him. Bottom line not a good professor he simply follows the book only less clearly, not a nice guy kind of a bully on the kids that asks questions and not approachable. Give your self a better clac 4 experience and take it with some one else you'll cover the same material without having to deal with this guy or the quizzes....
Jan 2010 
I do not agree with the below reviews Friedman is arrogant and does not like to answer question even though he think he is. He goes very fast (which to be fair could be just the class) but at the same time does not give enough examples to help you with visualizing what is going on. If you are someone who learns through proofs then go ahead take his class but if you need examples and problems to understand concepts then look elsewhere because Friedman is not your man. The handouts at the end of the semester are not teaching material even though he thinks it is. The homework for those handouts require much more work than most of the problem sets you've been doing all semester. The first test is easy (but so is the topic) the second test is not to say the least and neither is the final. If you are unfortunate enough to take his class he asks for definitions in his exams and expects specific words to be used. He also curves harshly and never defines how he curves. I took his class because of the reviews I saw below and was thoroughly disappointed.
May 2009 
This man is one of the clearest math professors I've ever had, hands down. His lectures are very easy to follow, and as long as you're paying attention his handwriting is relatively easy to read. Like the other reviewers say, he moves fast through the material, so if you stop paying attention in lecture for more than a minute or two, you're basically screwed for whatever you missed. He's pretty interesting though, and the material is cool stuff (compared to Calc III), so just pay attention in lecture and you'll be fine. If you stop him and ask a question, he'll explain it a different way without making you feel like a complete idiot. He's also very available and responds to email. His homework is about the most fair thing I've come across. A completely reasonable number of problems that line up really well with the lecture material, completely doable in 24 hours, due Monday morning. There are a few 15 minute quizzes at the beginning of class that consist of 13 short problems that are based on, if not from, the homework due that day. He puts up a syllabus at the beginning of the semester with all the assignments and corresponding book readings on Courseworks. If you pay attention in lecture and do the homework, it's very easy to do well in this course. The tests and quizzes are fair, the homework is fair, and you learn a lot. Frankly, it's hard to imagine a more straightforward class. Bottom line: take this class with Friedman. You learn a lot without it being stressful.
Dec 2008 
Great professor! He's really helpful and wants to make sure that you understand everything. He's INCREDIBLY available outside of class. His handwriting isn't as bad as people say it is... on the plus side, he speaks English perfectly. I'd recommend that you go to class; you'll get a lot out of it.
Dec 2005 
Dr. Friedman is an excellent professor who knows his stuff...however be warned! unless you ask questions, he moves very very quickly (so, stop him every once and a while and he'll answer your question without making you feel dumb). The homework is challenging but not mindblowing. Expect it to take between 1 and 3 hours depending on the length of assignment (and how smart you are!) Most problems are straightforward (even the proofs). My only complaint with this course is that it is not curved, and the tests are very easy (the medians on the midterms were 91 and 88). If you make some stupid mistakes you quickly get bumped below median! (That happened to me twice.)
Apr 2005 
As most of the other reviewers have already mentioned, Friedman is one of the clearest and most concise math professors I've had at Columbia. Positives: explains things very clearly and tothepoint, proofs are SO clear because he talks about every step and reasons them out instead of spilling math diarrhea onto the board. Negatives: writing can be hard to read, moves quickly on topics in class, has a tendency to stand in front of whatever he's writing, and then when he moves away he's on the next part of whatever he's talking about. Overall seems like a really nice guy, will occasionally throw things in during lecture about algebraic geometry (his research), and makes the material interesting. Would take another class with him.
May 2002 
If you are a (prospective) math major, or just a lover of math, you NEED to take a class with robert friedman. if not, run far, far away! as a fellow number geek, robert friedman rocks my mathematical world. his lectures are engaging and interesting...he goes at a very fast pace, but thoroughly covers the material. he is a fair grader and his exams are straightforward and almost predicatable. if you put a lot of effort into completing and really understanding the homework, you should easily do well on the exams/in the course, since generally the homework is much more difficult than the exams. highly knowledgeable and somewhat quirky, friedman is an excellent prof. although, i would advise any one who is not a math major/who has no interest in mathematics to avoid friedman at all costs.

Feb 2002 
I must disagree with the harsh review. Friedman seems like an overall decent guy who is making a genuine effort to explain the material. Granted, the lectures are not a carnival, but they are also not terribly boring. The lectures do move at a fast pace because the prof talks somewhat fast but if you force yourself to keep up, the class can be interesting.
Apr 2001 
He's a boring lecturer, I'll give you that. However, he does make an effort to answer questions in his office hours, and after class. His exams are straightforward, and the homework is short and easy. Do the homework, skip the class, study, and you'll probably get an A if you're smart. If you're not math oriented, stay far away from this class.