I told myself that I would wait until I was done with the class to really make sure that what I was saying reflected the class as a whole.

As you've heard, this class, for all intents and purposes, sucks. Do not take it if you have the opportunity. My caveat to most of the other reviews is that this not only was Barr's first year teaching, but he also was given the entire 20B course to handle on his own. I don't think he's the devil in Disney's clothing. I'm pretty sure his ideologies and test styles would have been a little more fruitful if he didn't have the entire 600 student load to work with.

On the other hand, there is a lot of things wrong with the class. The emphasis on group work, especially given the times that we are in now, was a miss. The lying to the students was disappointing. The tests that didn't really mirror content in the class were painful and disheartening. But the worst to me, and many others, was the refusal to listen to our complaints. I understand that he had research on how students work, but there comes a point where if 10s if not 100s of your students are asking for a simple answer document for your problem sets so they can confirm that they are grasping the content correctly as they cannot attend office hours for a multitude of reasons, maybe reconsider. The lectures also left a lot to be desired, as he would spend about half of the hour lecture answering questions that could easily be left to Campuswire, and the other half zooming through content that is sparsely detailed. He would be willing to spend an entire class on a derivation only to reveal that it wasn't content we needed to know but spend only a few minutes on concepts that were entire questions on an exam.

In summary, this class sucked. I wouldn't recommend taking it if you have the opportunity to do literally anything else. But, I think (and hope) that with time and actually listening to the students Barr could do better. It's clear that despite his shortcomings in translating it to the students, he has good knowledge of the content.

Professor was extremely interesting. No doubt he came to class super passionate about something, but honestly that something didn’t seem to be chemistry. He seemed more concerned about bettering his teaching skills than actually teaching. His use of varied resources was nice in theory but annoying in practice. He seemed to be trying to do too much at once, and most noticeable the grading suffered.

Barr tried to reinvent the wheel in a time when the students could have used some familiarity. His grading policy added unnecessary stress on top of a stressful time. Early on he didn’t seem sure about how the grading would work out and tried to pass this off as a normal thing even though he is literally the one who decides. When describing the class he was frequently vague and occasionally told hopefully unintentional lies about how the class would be set up.

He provided resources to support us but the OWL quizzes were essentially a waste of time assigned a point value. His problem sets were key to gaining understanding but his defiant no answer key stance made no sense. Office hours in this class were necessary to tie everything together and the most efficient way to prepare for the exams, since there answers to problems that Barr wrote could be obtained.

The exams were highly tangential. Several concepts on them were ignored in class but highlighted in review sessions meaning that these were essential parts of learning in the class. Midterm 2 was unnecessarily hard and only justified since the Final would replace a worse midterm score.

There was a group component to the section, leading to the possibility of time zone shenanigans. These sections were ok as the problems we did seemed helpful and more in line with the exams. It really depended on how good your overall group was.

Overall, this class wasn’t good for students trying to actually learn chemistry. It seemed highly hostile to those abroad and with time restrictions. Barr was not accommodating but said he was. For students who know the material already and are just looking to advance towards a major, this class will just be a minor annoyance and probably has less REQUIRED work than other chemistry classes. If this isn’t you then it probably isn’t worth taking the class unless you are prepared to go to many office hours or, like me, have no problem trawling the internet for chemistry resources.

TLDR: Not a fun class for those who don’t have a good chemistry understanding but hey, at least the lectures looked pretty.

Straight to the conclusion, Barr deserves a much better score than 2.3, at least in the Spring quarter. I gave him a 5 (more like a 4.5)
From my experience in the spring, I would recommend him. His lectures are not bad, for him being a funny and engaging lecturer, though he sometimes goes off topic....; He gives a LOT of assignments(many of which are VERY EASY TO MISS, BE CAREFUL), so the workload of this class is heavy, though the good part is that they boost up your grades for them being easy 100s; The tests are difficult for sure, (cuz it's chemistry), but they are on topic and relatable to the class content (a GREAT improvement from winter as I looked at the past tests). Grading is fairly generous and based on a curve. (Class avg for tests in my session are like mid-70s, so an 80+ would probably give you an A unless there are too many prodigies alongside); Group participation does matter, good thing is that this time he lets us pick our own team. And I appreciate him for this because my teammates and LA are GODSEND!! what I dislike about him is that grading for him takes forever, expect more than 3 weeks for each test.....
A big problem about him is that he gave us problem sets as test review materials (not part of the huge workload), but there are no answers (which make the problem set meaningless), you are completely on your own and the only way for help is OH/review sessions which is not enough. luckily my GODSEND LA gave me his solutions and helped me review, so I didn't suffer so much.
20B in general is not as hard as 20A, most of the contents are reviews/expansions from AP Chem topics. If you did well in AP then you should ace this easily, if you didn't then don't worry, there won't be any quantum mechanic shits like that in 20A.
I had friends who took him in winter and I understand all the earlier negative comments about him. There still are many parts of him and his class that I find it struggling, but he actually listens to students' complains and suggestions I have seen those improvements made in spring. Since he is a new prof. so be easy on him, plus he is a very approachable and friendly teacher. For future students, if you find it struggling in his class, write something serious and helpful in Bruinwalk or direct email so he can improve and teach better.

it's true it was hard. I know I failed that final. but honestly, the best part of this class and Professor Barr is the environment he creates. He encourages us a lot and everyone is pretty much working together and struggling together and dad jokes and chemistry puns at the beginning of lectures are always funny. This is the professor's first? class I'm pretty sure and even though the exams are difficult, and class is painful, the social aspect is pretty good too, especially in this online environment. So expect to have a good time but work hard for a good grade. He doesn't curve but also the percentages are kinder.

There are a lot of things wrong with Barr. I think he was very unfair to international students--he gave exams the same day as lectures at an awkward time, and he doesn't tolerate if your Internet goes out. There are a lot of small assignments that can be hard to keep track of (I hate those damn surveys). His lecture style is really annoying because he talks to you like a 5-year-old. His "empathy" for the class is pretty disingenuous (understatement of the year).

Where I disagree with the other reviewers is that the overall difficulty is pretty on-par with a lower-div chem class. In no way am I justifying his exam style/design, but at some point that's just the reality of these classes. So I don't think you should "avoid him at all costs" (especially because he might be teaching it next quarter). Just try to read the textbook as much as possible and be careful if you have extenuating circumstances, because he is very intolerant about them.

We were told one midterm would be dropped. The second midterm was so. much. harder. than the first. And instead of curving the test or offering corrections or SOMETHING to rectify, he simply blamed the difference in the fact that we were all "shocked" because it was the second midterm was in person. I was the type to get an A+ in 20A. This class was difficult to the point where I couldn't even scrape by with a B+. Not that we were told the grade scale. Anything between a 76% and an 88% were "some flavor" of B. So we can't really ask to see our grades, because we have no idea what constitutes a plus or minus grade. He also does not have a place to monitor your grade. He has excel sheets that you can use to estimate your final grade after each midterm, but again, you are only told what "flavor" of grade you are on track for. So you don't know if you are on the verge of dropping or increasing by a letter grade.
He also talks to us like we are high school students. He doesn't seem to realize that most of us have become very good at teaching ourselves things, so doing something like giving solutions would allow us to teach ourselves. He do be gatekeeping.

Okay... so I'm sure you've already seen a lot of the other reviews... BUT I'll say that most, if not all of those were written before the final exam. Going by what the final looked like, it seems that he's starting to improve based on this criticism so that makes be hopeful for future classes. It kinda hurt to see all these negative things being said about him because he really does seem like a genuinely nice person. As a teacher though, I'd say a fair amount of that criticism is warranted. But of course, this was his very first class ever, and we can't expect him to be perfect right off the bat.

Look, I didn't really have a good time in this class, I'll be honest. But I also don't think getting a class with Barr is a death sentence. He can only improve from here, so I sure hope whoever's reading this in the future will have a better time than I did.

Really caring but a lot of work!

I have never been so worried about not passing a class till I took 20B with Barr. After having Felker I was so ready for a new professor who would actually teach me chem. Well, I quickly realized that wasn't the case. I would go to lectures feelings completely overwhelmed and lost (which was mostly because I suck at chem.) He kinda goes his own way with certain topics like entropy he says "I know most people say it is disorder but I don't like that so that's not what it means." Which was the easiest way to understand such a conceptual term. To understand any of what he was doing, I rewatched lectures over and over again and used youtube, chemlibre and a million other resources. Also, I tried going to OH but he calls on random students which stressed me out so much because I was usually clueless. The problem sets didn't have an answer key so they seemed pointless to do. OWL was also a waste of time. Also, he has us put into groups of three-four to do homework sets which were ONLY assigned during the weekend (6pm Friday to 10am Monday) and all my group members as well as me worked weekends so it was extremely difficult finding time to meet. The midterms were beasts. He also promised us we would have our grades back within a week and we didn't get the final midterm 1 grade back till 2 days before grades were due for the quarter. We never knew how well or bad we were doing because of this and there was no curve but everyone claims to have done wayyy better than anticipated. I ended up switching to P/NP after he told us we HAD to get at least a 50% on the final and judging on my midterm grades this seemed more daunting than it should have been. I know Barr meant well but at the end of the day just avoid him unless he fixes the many mistakes.

This class was rough...throughout the entire quarter I honestly felt like I was failing because the midterms were so applied (like verging on bio tests applies). The biggest problem is that Prof Barr doesn't give answer keys to problem sets, so you have no way of knowing if what you're doing is right. I did pretty badly on Midterm 1, which ended up being dropped for the final. The final was actually way easier than the midterms, so hopefully he's learned that his super applied tests aren't the way to go. Homework is a large part of the grade though, which is easy to get 100% on. And he does offer extra credit. So our grades ended up being ok in the end, but the journey was rough and I'm so happy to be done with this class.