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.

Barr is one of the few professors who really seemed to care about his student's learning. He often gave surveys to students to asses how effective his lectures and assignments were and made an honest effort to improve and implement suggestions. In addition, he and his TAs had multiple office hours every day, so if you were ever confused on a topic there was always an opportunity to ask somebody. The midterms were certainly a stretch, with many of the questions requiring you to take what you learned in the class and apply it to a novel situation. This meant that the midterms were much harder, and even if you knew all the material perfectly you could still stumble as you have to apply the materials in new ways. However, to counteract the difficulty the midterms have a group component, allowing you to get many test points by going over the midterm with your group and resubmitting it. The final was much more normal and easier, with straightforward questions that covered the content (and it replaced a midterm score). Discussion sections made you go through questions with your assigned group, which provided good studying material as the questions were similar to test and PSET questions. The way his class is graded is somewhat confusing as he refuses to give a straightforward curve, he instead says that points gained from (rather easy) HW assignments and points from the surveys act as a "curve". I disagree with having the midterms be so difficult, but the final is reasonable and the rest of the class is filled with many opportunities to learn and improve. (NOTE: This was his first class as a professor, he stated multiple times that he was evaluating his course and technique and planning on implementing changes, so his future courses may be different than what we experienced)

Lectures:
Barr seems knowledgeable about chemistry, and his lectures might be helpful if you already have a decent knowledge of the course material (maybe if you took AP Chem). If you do not have a working knowledge of what he is talking about, you will probably be left behind. The lectures themselves seemed to make sense, but he often skipped steps, making simplifications when solving problems that he seemed to assume we would understand despite him never really explaining them. Take good notes. Anything helps.

Homework:
The OWL assignments seemed easy enough, and we had more than enough attempts at each problem to get 100% and get a brief understanding of a few topics. However, they were very short assignments and the problems were nowhere near the difficulty of tests. They were helpful for a first look at concepts, but don't use them to study. It won't help.

The Textbook:
If you took 20A, it's the same one. I would use ChemLibre or Organic Chem Tutor instead.

Tests:
DIFFICULT. Study. He writes them himself and they won't be what you expect. The questions are mostly pretty fair if you really understand the material, but there are multiple reach questions per test. For example, stretching the course material to apply it to current topics in biology, theoretical questions about geology, etc. They are also timed with a strict submission period. He also includes material that he teaches on the same day as the test.

How to Study:
Do the problem sets. I wish I would have done them every week when they were released. They are long, but are really the only way to study. Unfortunately, he won't give you an answer key, so you'll have no idea if your hours of work were going in the right direction. Make sure you have some kind of study group to ask about pset questions and try to make a group answer key. Problems at the end of the textbook chapters would probably also be helpful if you have any time to do them after finishing the problem sets. Also, watch Organic Chemistry Tutor on YouTube and use ChemLibre. They explain things a lot better if you need it.

Empathy?:
Barr constantly says that he "empathizes" with students, but he won't do anything to help them. I think this happened in basically every lecture. Most notably, he insisted on only having one time for tests for every lecture and time zone. Like every student in any lecture took the test at the same time. It worked for me, but some of the international students told him that they would have to stay up late to attend the lecture and then wake up at like 5am for the test. He said he was very "empathetic", then proceeded to do absolutely nothing about it, continued to include material from the same day's lecture on tests, and made no effort to find a way to make the timing work better. This kind of thing happened a lot. He seems to want to appear empathetic, but it's not very genuine.

Grading:
You need at least a 68% in the class and a 50% on the final to pass. Your final grade can replace one midterm. That sounds good, but definitely don't count on doing well on the final. The one redeeming factor of this class was that it seemed like tests ended up being a relatively small portion of the final grade. If you get over 50% on all the tests you should get a C. Based on a poll we did in the group chat it seemed like most people passed, so that's good I guess?

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!

The tests are so much more difficult than what he actually prepares you for. Even with excessive amounts of self-teaching and absolute devotion to studying for the tests, the tests kicked my ass. He is a really nice person, he tries so hard to be a good professor, and he really puts in an effort for the class, but he just doesn't give tests that are reasonable for what you learn.

Do not take this class with Barr if you can avoid it. Unfortunately, he was the only 20B professor this quarter, meaning I was stuck with him. I thought that my knowledge from AP chem would be enough for me to get through this class rather easily, and up until the first midterm, his lectures reflected that belief. His lectures make the material seem pretty reasonable; however, his "optional" problem sets (that he doesn't provide answer keys for) and his exams display how surface level the topics covered in his lectures are. He covers the bare minimum during lectures, but then tests you on a much deeper and confusing level. His lectures are also very chaotic, start five to ten minutes late, and are extremely rushed.
The first midterm was pretty confusing, but it was nothing compared to the second midterm (class average was around 60). Barr's exam questions don't test you on your mastery of the topics; they test you on how well you can decipher his bullshit in order to figure out what he is actually saying. His questions are long-winded, convoluted, usually are on things never covered during class, and are only vaguely connected to class material.
Barr also likes to pride himself on having his students interact with him, the TAs, and other students. None of this interaction is voluntary. His homework assignments, two of which are due right before exams, are completed in groups assigned by the TAs, and are significantly easier than any test question, making them time-consuming busy-work. Barr "encourages" his students to do the problem sets and come to his office hours, but it is clear that these things are necessary in order to do well in his class.
In the beginning of the course, he says that he goes over problem sets in his office hours instead of providing answer keys. I only attended a few office hours, but during this time, he rarely completed a full problem set, leaving the other questions unanswered and was unwilling to provide the answers.
Ultimately, this class is too much work and purposely made more difficult by the exams. Barr seems like a really nice person, but is an unorganized and stress-inducing teacher.