Professor Yoon is one of the best professors I have ever had. He is an incredibly passionate, bright person who managed to make a notoriously difficult class into one of my favorites. He is very active on piazza and gives lots of opportunities for practice which is super important for a course like this. I wish every prof was like him.

I wish Tehshik ran the entire undergrad chemistry department! He is a clear communicator, empathetic to the student experience, and makes the course accessible and fair. He points out areas of organic chemistry that are relevant to life and other science disciplines.

TPY has been my favorite professor thus far at UW. He was always very clear on what he expected us to know, gave great problem sets, and genuinely cared about his students. Yes, the content was very difficult, but he never downplayed the difficulty and prepared us accordingly for it.

TPY is by far my favorite professor I've ever had at UW-Madison. He is clearly very passionate in what he teaches, and made me excited to come to an ochem lecture (unthinkable, right?). He is very intelligent and explains everything super clearly. I would recommend him to anyone taking chem 345, though I believe he only teaches in the fall :(.

He has so much passion for whatever he is teaching. I don't know how there could be a better professor for Ochem 345! I hope to have him again for future classes.

Professor Yoon is arguably THE best chemistry professor at UW-Madison. He made organic chemistry interesting and engaging. He also was extremely down to earth and sweet. His grading criteria is very fair and never out of the ordinary. He provides lots of practice problems, which are crucial to performing well in the course.

Professor Yoon is the best professor of chemistry I've had out of the 3 courses I've taken and possibly one of the best lecturers in UWMadison. His lectures introduce a complex set of reactions in an organized, clear manner and make solving chemistry questions akin to solving a puzzle. Furthermore, the course is built to benefit the students.

I HATE chemistry with every fiber of my soul, but Yoon was genuinely one of the best professors I've ever had. He is so incredibly passionate about the subject and it makes you want to love it as much as he does. He understands students and isn't unrealistic with his expectations for the class. Would recommend 10000/10!!

The content is hard, but TPY is so engaging and shows a clear passion for it that it makes it easier to learn. He is also so kind and helpful if you go talk to him, so if you need anything you should always ask him. Literally the best lecturer I've had at UW

TPY gave great lectures! He was clear and concise with his expectations and never tried to trick you. Problem sets and practice exams are reflective of the actual exams; I would say the problem sets were actually a bit harder. Only tough part is how little extra time you have on the midterms to look over your work.

Tehshik Yoon was a phenomenal professor! Take it from someone who got a C in 343 and hated the whole course, he made me LOVE orgo. I was sad to finish this class - from the very first lecture to the very last Yoon was engaging and encouraging. Never zoned out. He cares about students' success and the practice based learning he preaches truly works.

Very passionate about what he teaches, made the class seem more fun. Highly recommend taking this course with him as the professor.

TPY makes lectures very clear and exams are very reasonable. The exams are meant to be on the easier side so time is your limiting factor on exams. Yoon is very funny and approachable. As long as you practice, you can succeed in the class.

I don't even know where to begin... Yoon is a great prof and made O-chem seem more important and manageable. Lecture attendance wasn't mandatory but extremely recommended; also lots of textbook reading. Dr. Yoon incorporates a lot of dry humor into his lectures which often catches you off guard, and encourages hard work and engagement. Loved him!!!

Prof. Yoon genuinely cares about his students. If you reach out to him for help, he will help you until your question is answered. Best chem professor I have ever had at UW-Madison.

Professor Yoon is honestly one of the best professor's I've had in college so far. It is clear how knowledgable he is in chemistry and how deeply he cares for students. O-chem is naturally a tough class, but Yoon made material manageable and provided resources to help students succeed. I highly recommend taking his class if you can.

TPY is the BEST professor I've had so far at UW Madison. His lectures are very engaging, he is very clear and well spoken and knows exactly how to explain the toughest concepts. He is so helpful in office hours and genuinely wants the best for everybody. Writes fair tests and does not try to trick you. Makes chem interesting and dare I say--fun !!

One of the best professors Ive ever had. He truly cares about teaching his students and ensuring they understand the content. Very fair exams and lots of practice avaliable. He has many years of teaching experience and it clearly shows. Would definitely recommend for chem345.

I was worried about this class but Yoon made it awesome! Forgiving with grading, allowing the lowest test score to be replaced if you do better on the final. Hand picks problems from the book that are good for practice and also makes practice problems. Super nice, funny, and understands his class is hard. Would definitely take another class of his.

You will need to go to class to get the information but he makes going to class a delight. Offers low-stakes concept quizzes to check understanding and will clear up misconceptions if the class struggles on one. Resurrection final that can replace the grade of a previous exam if you do better. This is what higher education aspires to be.

He has a forgiving grading system (basically worst test score gets dropped) and it saved my grade. Homework is mini quizzes on lecture content that are worth points, but you only need around 2/3 of them right to get full points in this category and they're helpful while studying. He is super friendly/nice and I'd 100% take a class from him again!

He carries all the best qualities you dream to find in a professor. Awesome lectures, knowledgeable, really patient on explaining things again and again make sure you gets it. Really make time to help you. In general hes fun and really passionate about what he teaches. If you have a chance to be his student, youre so lucky.

With new online learning at UW and events outside of class that have distracted me, I haven't interacted one-on-one with Prof Yoon; this is one of my biggest regrets. His teaching style is amazing, and his correspondence and interactions with the class are unimaginably considerate and caring. This class is hard, but he makes it so worth it.

Professor Yoon is the best professor I have ever had in UW-Madison. I would like to provide more comments about his lecture. His lecture is very clear, in-depth, and inspirational. I always found his lecture very easy to understand. Even though he mentioned textbook content may be tested, if you fully understand his lecture, you will be good.

I loved having Prof Yoon. He is without a doubt my favorite professor I have had thus far at UW. He made online learning so manageable and his explanations were always crystal-clear. If you have a chance to take this class with him, DO IT! I promise you won't regret it. He's a gem.

Yoon was honestly such a kind and accessible teacher. In a class this challenging and with the stress of online schooling, he managed to brighten the days we had live lectures with his cheery and helpful personality. Truly happy that I was able to be a student of his! His class was also the most organized class I have taken, in person included!

He is pretty enthusiastic. He ask us to learn through pre-recorded video lecture and he use the class for problem solving and group discussion, which is a really effective arrangement for ochem. Hes explanation for problems is always crystal clear. He encourages students to explore their own ways in problem solving and fall in love with ochem.

I think the best words to describe Professor Yoon are optimistic, patient, and inspiring. His passion for chemistry made me appreciate the subject more, not only because of his obvious excitement, but also because of how willing he was to answer all questions. I also enjoyed his pep talks; sometimes I felt like he was my chemistry therapist.

Yoon is AMAZING. Literally the best professor I have ever had. Ochem is supposed to be challenging but he made it so much easier to understand. Honestly made me love ochem (or I might be crazy idk). You can tell he cares a lot about his students and wants everyone to succeed. Take this class with Yoon, you won't regret it.

Professor Yoon was the best professor Ive had to date. Hes a very thorough grader and thoughtful professor and hes one of the best chemistry professors at UW. It was a real pleasure to have him as a professor. If you have the chance to have him as a professor, dont take that for granted and ask loads of questions!!! Its helpful :)

Professor Yoon is an AMAZING professor! Probably one of the best one's I've had at UW. Especially for a class as hard as ochem, he makes every topic so much easier to understand and puts in so much effort to make sure his students succeed. 10/10 recommend!

Professor Yoon is by far one of the best instructors Ive had at UW, despite teaching one of the most notoriously feared classes in the department. Hes an amazing guy and fair grader who cares a lot about the well-being of his students.

Dr. Yoon is excellent. I dropped 345 in the spring semester and had Esselman. Night and day comparison. Yoon's exams are very fair. During the pandemic, Yoon was incredibly accommodating and understanding. He actually cares about is students and is so prompt to respond. In such large classes, I have never seen such passion for helping students.

He was an absolutely AMAZING professor this semester!!! He is always willing to help you out if you don't understand the material. His exams are definitely challenging, but that is part of what makes you work harder to succeed. Overall, I HIGHLY recommend him for Chem 345 in the future!!!

Prof. Yoon is the best chemistry teacher I have ever had, I took second semester organic chemistry with him and he made everything seem so straightforward somehow. I would highly recommend searching him out for any of his chemistry classes. He also cares so much about his students, even in the online format you can tell how kind he is.

Tehshik is a phenomenal professor. He cares about his students and the subject matter. The content is challenging (as with any 500 level class) but he will work hard to ensure that you have a complete understanding. 10/10 would take this class again

Dr. Yoon is the best chemistry professor I've had at the UW. His lectures are amazingly clear and he's always willing to answer questions and help you out. Homework is optional but the more you do it the better off you are on exams. If you can take a class with Yoon do yourself a favor and take it.

Tehshik Yoon is one of the best lecturers I have ever had in any class - I'm an exchange student from University of Sydney, perhaps rivalled by another lecturer I had at home but it would be a close call. The only minor issue I might have with his style is that he can be a bit fast but is clear, very helpful, and likes upperclassmen (ie 547).

This was by far my favorite class taken at UW-Madison, Professor Yoon sincerely cares about student success, is passionate about teaching, and is an organic chemistry master. He also is great about answering questions in class. You need to attend class and pay attention, but if you put the effort in you can certainly succeed in the course.

Honestly took the class with the expectations of it being extremely hard especially since I took it was the lab (344). The lab turned out being the funnest most stress free chem lab I've taken so far and helped SO much when you study spectroscopy in 345. Yoon is by far one of my fave chem teachers and made 345 very interesting and challenging

If you have to take Ochem 345, take it with Yoon. He is by far the best professor I have ever had. He makes class interesting and exciting, while also giving clear explanations for very difficult material.

Ochem is inherently a difficult subject, but prof Yoon makes it interesting. He is enthusiastic and great at explaining mechanisms. One of the best in Madison's prestigious chemistry department!

Yoon is super energetic and makes the lecture so much more interesting than ochem should be. However, his exams are completely unfair and impossible. He is cheerful and kind and funny but the class definitely made me cry... a lot

Ochem is a hard class, but Yoon is simply the best. He is really clear and really helpful. So to all you freaked out pre-meds that HAVE to take ochem (like me)...take it with yoon!

He was an AMAZING professor!! By far the best in the chemistry department. He was very thorough and was very helpful in office hours. Only issue was he talks very fast during lecture. But he encouraged questions during lecture and wants everyone to learn, not just memorize the material!! He also has a group on fb that was very helpful.

Awesome professor. Go to office hours, it's more of a mini discussion because there's always at least 5 students there-really helpful. Don't be afraid to ask for points back on the problem sets, I got points back on every one by asking him about it. Take ochem with him, seriously. LOVED this class.

Yoon is one of the best professors I've had. He made Ochem enjoyable. He often suggests to not use notecards to learn the material but his exams tend to be synthesis heavy so notecards do actually help. The exams progressively got tougher but doable. Make sure to attend office hours especially for the problem sets because it is very helpful.

Yoon made O-chem suck a lot less. He is really clear, cares about the material he teaches, and tries to understand his students too. He is slightly narcissistic, but he's good enough that most people might not even notice. Definitely recommend for any o-chem course.

Yoon is honestly the best professor I've had thus far. He speaks clearly and with purpose. Everything word is meaningful while keeping lectures interesting. Exams are rightfully challenging and fair. Help if availible around every corner. HIGHLY RECOMMENDED

He is an amazing professor! Everyone knows Chem345 is a tough class, but his exams are fair. He is enthusiastic in teaching and will make you not wanting to miss lectures. I hated Organic Chemistry before taking this class, but walked away inspired and motivated.

Great prof in lecture but its totally deceiving..in front of 300 students he is lively, energetic, & seems nice, but one on one hes a completely different & rude person-its actually kind of scary how he turns stone cold. Doesnt have office hours & truly avoids meeting outside of class. Not a good professor if you want outside help & someone nice.

Amazing prof! If you ever get the chance to take him, please do. He is really clear, but goes a little fast. Exams are totally fair, and he is always available to answer questions through AIM and Facebook. Yoon made O-chem fun and interesting!

Yoon is awesome. Class was easy and the exams were not difficult at all. Got a 100 on the final and there were quite a few students that got over a 95 on the final. Quizzes are relatively easy, I actually thought the take home quizzes were the hardest. Will do anything to help students. Yoon himself is very distinguished went to Harvard and CIT.

Amazing man. Amazing professor. Take his class, you won't regret it.

Awesome guy. Really reaches out to students and wants you to succeed. Class isn't easy, but having a great professor really helps

Best Professor I ever had! He is extremely intelligent and unlike many professors, he is actually interesting to listen to, not possible to fall asleep in lecture. Listen to what he has to say in lecture and write down more than he put on the board, he talks quite fast but is very clear. Not to mention he is charming, amazingly handsome :)

Prof. Yoon is a fantastic teacher.

If you ever get a chance to have a class with Prof. Yoon, consider yourself lucky! He is easily the best professor at UW-Madison, and is highly distinguished throughout the country! Tests can be difficult, but doesn't try to trick you. Attend lectures and enjoy his style.

Lectures are very well organized and easy to follow even though they do go really fast. Professor Yoon genuinely cares about his students and their understanding. He even has an AIM account that he goes on pretty much every night so you can ask him questions with out going to office hours which is really convenient.

Best professor I've ever had. After having 343 with Ress, I learned how much more effective it is when the lecture is done on a chalk board as opposed to power point. He flies through information but you usually get out 15 minutes early(power lecture). Tests are tough a but curve makes it fair. Makes me want to major in Chem to have him again.

Prof Yoon is a champion. Weekly quizzes that are necessary or we would fall way way behind! Exams are a **** but he curves well. Teaches with grace and beauty only found in the most elegant angels of the lord. Seriously, he teaches awesome but he goes really, really fast. Suck it up and enjoy the the classical music before every lecture.

Tehshik Yoon is the best professor I've ever had.

One Word---STELLAR! Easily the best prof I've had at UW. Very clear and concise, and engaging. He goes on AIM nearly daily (afternoon + evening) to answer questions! Exams tough but class is curved--no worries. Goes a bit fast in lecture so practice drawing molecules, but still able to keep up okay! Mean of the class is said to be a B. TAKE HIM

Amazing teacher. He is incredibly knowledgeable and explains things very well. The only problem is that he writes and talks incredibly fast. Easy quiz every week if you come to class. Exams are difficult!

Good class, was really useful and fun. Prof is hot.