Below are the overwhelming amounts of positive comments that my students have left for me each semester. I have hand picked the ones shown, these represent slightly more than half of all comments I have received - even the ones not displayed are overwhelmingly positive. These are anonymous quotes directly from the Instructor Evaluation reports; I have not edited any of them!

Spring 2019 - Math 240 (McGrath) - Won TA Award ~40 Students

TA Quality: 3.63/4.00

  • "The excellence in TAs redefined what education can be at Penn. Although this class was a lot of work, it was by far my favorite class this semester. Yes, there was a lot of complaining and groaning, but if every class was like this one studying would be a lot more enjoyable."
  • "Everyone knows that Ivan is an amazing TA, and I am not at all surprised that he lived up to his reputation. Not only does he genuinely care about his students and their performance, but he also understands what it is like to be an undergraduate and especially an undergraduate in this course. His resources, recitations, and general advice was incredibly helpful and definitely improved my performance in the course. I was incredibly lucky to have him as my TA, and I'm sad to see him go but he definitely left a great impact and set a precedent for Penn's math department and Penn TAs."
  • "Please don't give a ridiculously long homework assignment over spring break. Thanks!"
  • "too much recitation homework"
  • "Fab TA, but could you not take off so many points? The hw is hard as heck there is no need for this Ivan, I thought we were friends."
  • "Ivan and Nibby are the GOATs and I will miss them a lot next year when they leave. They hold plentiful office hours and are always open to helping us students and it is mostly through them that I was able to do okay in the course."
  • "Ivan was probably the best TA I ve ever had. He is very patient and a clear communicator."
  • "Ivan Li will forever be the best TA that Penn Math has ever had."

Fall 2018 - Math 240 (Maximo) - Won TA Award ~80 Students

TA Quality: 3.89/4.00

  • "This recitation was amazing! I learned so much from Ivan's recitation as well as his additional materials that he provided. Ivan was always accessible and easy to reach, and I had no difficulties whenever I had questions, concerns etc."
  • "Ivan is hands down the most hepful ta I have ever had. The amount of work he puts in to help us, like the videos and notes on his website."
  • "Ivan Li was the best TA that I have had at Penn. He really helped me learn the course material and was accessible outside of class."
  • "Ivan is the best TA I have ever had. He is so passionate about what he does. He is so helpful, and I would have done so much worse in this course without him and all of the resources he provides."
  • "Amazing TA! Truly cares about teaching us what might have been lacking in both lecture and the class."
  • "I really enjoyed Ivan's recitations, and appreciated that they were recorded every week and uploaded for the students to access because it helped me go back to something I might have not completely understood during lecture. I also appreciated that he gave very thorough review sessions because they were extremely helpful for studying for exams."
  • "Ivan is literally the best, would not have gotten through the class without him. THANK YOU IVAN!!!"
  • "Ivan is the most engaging TA I have ever met before. He goes above and beyond (literally) to make sure we understand the course concepts. He exceeds any and all of my expectations."
  • "Recitations helped guide me through the class and provided a lot of structure to a very disorganized lecture. Ivan was very accessible outside of class, and he responded to emails within a few minutes, and I was able to schedule meetings to go over midterms, practice problems, and just general questions about concepts multiple times. When I felt completely lost in lecture (which was most of the time), Ivan helped make the concepts easier and stimulated my interest when I was no longer interested in the subject because of how much I was struggling. He goes above and beyond through his videos on his webiste, extra extensive review sessions, and being available at all times."
  • "The recitations were beyond helpful; Ivan was a great TA who put a TON of effort into office hours, recitations, review sessions, and much more. His videos really helped to solidify my understanding of the topic and I feel so lucky to have ended up having him as a TA because I don't think I would've enjoyed the class as much or learned as much had it not been for him."
  • "After taking this course, I think it's safe to say that a new statue should be erected outside DRL which bears the name of Ivan Li."
  • "Ivan Li was an unbelievable TA. The amount of time that he put into recitation materials, holding review sessions, answering questions, etc. helped me to understand the material clearly and to study effectively. I do not know what I would have done without Ivan as a TA. Many points of the lectures became confusing, and Ivan always had a clear and concise way to explain the topics. I cannot thank Ivan enough for his dedication to help us learn. The best TA I have ever had at Penn by far."
  • "IVAN LI IS THE GOD OF MATHEMATICS. I love that he goes above and beyond for his students, providing material in the form of videos posted on his website. He also provides us with additional problems (and solutions to refer back to) whenever we have exams. I think he does an awesome job of explaining concepts that would otherwise be difficult to process. I'm so glad I got him as a TA this semester!"

Spring 2018 - Math 240 (Chai) - Won TA Award ~45 Students

TA Quality: 3.95/4.00 - Highest 240 rating ever (min 20 students)

  • "I did not attend a single lecture and only learned from my TAs office hours and recitation. He singlehandedly is the reason I passed / learned this course and was absolutely amazing."
  • "Ivan has taught me two semesters of Calculus at penn. Less than 10 students attend lecture because no one can understand the professor, but Ivan is able to teach the curriculum in only 50 minutes each week."
  • "Ivan is AMAZING! He is always accessible outside of class, either in person or through email/Piazza. His notes were very helpful and prior to all exams, he held review sessions where he went over problems that we needed to know for that particular exam. He is very patient and kind and I can confidently say that I learned and understood material from this course only because of his guidance and teaching."
  • "Ivan was simply incredible. I usually don't attend office hours for any class, but I emailed Ivan often because I knew that not only would I get a prompt and accurate response, but that he would go above and beyond in helping me understand. Just before the final I asked for help on a Pimsner problem. Ivan (accurately) informed me that we had not covered that topic, but also highlighted what I should take away from that problem anyway. He is simply excellent!"
  • "Due to the poor communication of the professor, many of the students in this class (myself included) only show up for recitation with Ivan (Yilun). He teaches the class in a much more understandable and manageable way than the actual professor, so much that other students from other sections of the class (with different professors) come to his review sessions because he teaches the content so clearly and with such poise and confidence. I literally only am passing this class because of Ivan. He has put in so much time and energy to provide his students with extra material like practice quizzes, answers to practice problems, review packets, recitation notes, and even an 85 page notes packet. Ivan is an incredible TA, when I heard he was going to be my TA I knew that my life taking this class would be easier."
  • "Ivan is an amazing TA. His teaching is always clear, concise, and to the point."
  • "The TA went above and beyond to help us learn the material - he has even created a website and posts lesson videos for us."
  • "Ivan filled the void in my knowledge left by challenging lectures and opaque office hours with Prof. Chai. Recitations largely replaced lectures. I came to truly grasp and understand the material in Ivan's office hours. Study sessions held by Ivan filled classrooms while more and more students abandoned lectures. Ivan's website made accessing notes, videos, and practice quizzes for this class trivial. Ivan quickly and effectively responds to questions on Piazza. Even when Ivan hits rough patches in his unthinkably busy schedule, he still makes time to teach and answer questions for his student. Ivan raises the bar for all TA's and is inspiring as a student and a teacher."
  • "Learned the entire course from his great recitations. Ivan spends a lot of time preparing material for his recitations and review sessions. He is truly, an amazing teacher and TA. I took the course with Chai, despite his reputation, so I can have Ivan as my TA. Great and hardworking individual."
  • "Ivan was an amazing TA!! His recitations were filled with many useful examples, which helped clarify what we learned in lecture and prepared us to answer similar homework questions. He always went above and beyond to help us. I joined this class a week or two into the semester, and he was very accommodating with catching me up on assignments and helping me get used to the material. He had plenty of weekly (sometimes even daily) office hours, review sessions before exams, and was constantly answering our questions via Piazza. He also responded quickly to emails. He also updated his website frequently with his personal notes, extra supplemental examples, videos, etc. He was a fair grader and helped me understand my mistakes. I definitely feel like I would not have been able to succeed in this class without having him as my TA. He was somewhat apologetic that this was his first time as a TA for Math 240, but it certainly did not show, since he did a fantastic job!"
  • "IVAN LI SHOULD TEACH MATH 240 (and 114). Although I was unhappy to be stuck with Chai as my professor, I knew I was going to be ok because Ivan was my TA. I honestly had to remind myself that Ivan was also a student and not just our TA because he put much more time, effort and care into our class than Chai did. Ivan would stay an hour to an hour and a half past his designated office hour times to help us finish our math homework and make sure we understood the material. I am upset I will not be having him as a TA next semester because he has made the most significant positive impact on my math experience at Penn. I hope he goes on to teach because he has a gift for it and should put many of the math professors at Penn out of jobs (or teach them how to be teachers)."
  • "This TA was better than the teacher. I had him last semester for Math 114 too, and he continues to be amazing! He is the only reason I actually learned anything this semester. He will be a great professor someday"
  • "Ivan is the best TA there is, perhaps better than the professors with PHDs. If I have learned anything from Penn Math, it is from Ivan. Penn needs to find more TAs like Ivan, or have Ivan."

Fall 2017 - Math 114 (Haglund) - Won TA Award ~70 Students

TA Quality: 3.90/4.00 - Highest 114 rating ever

  • "Ivan was honestly a shining star in this class. I know he's only a TA, but he's probably the best instructor I had my freshmen year."
  • "He's an amazing TA. He taught me much better than the teacher did, answered my questions much more effectively, held a lot of review sessions, answered questions on Piazza quickly and is very likeable."
  • "Lectures were not the best way to learn the content for this course, but Ivan did a really amazing job going over everything that we needed to know. Math clearly isn't my strong suit, but Ivan took a lot of time to answer my question during office hours, as well as just provide a positive environment to learn. I was really intimated by my peers, and even though Ivan is pretty much a genius, he's still very approachable and encouraging. Thank you for a great sem!"
  • "Ivan did more for the students in the class than the professor. He conducted review sessions, gave review lectures on Fridays, and had a website where he posted notes and practice problems. He was always available and TRULY cared about us as students and individuals. Penn should do everything in its power to keep Ivan in the math department as long as possible."
  • "Ivan dragged us through Heaven and Earth in order to make sure we understood the material. This recitation was infinitely more valuable than the lecture and I cannot stress that enough."
  • "Ivan went above and beyond to ensure that students (and sometimes not even his student) were learning to material. The material he provided in addition to the extra review sessions that he has, and the extra office hours have overall helped my ability to learn in the class. During office hours, students had the opportunity to learn one on one with Ivan, going through practice problems, and he typically did a great job of teaching the material in a way where everyone could learn it. Overall, I'm highly impressed with Ivan's dedication to his students."
  • "I couldn't have survived through this course without Ivan. He invested so much time and effort to make course content more manageable and understandable through recitations, Friday review sessions, office hours, exam review sessions. He also had a Piazza page which was such a nice way for us to ask questions to both him and fellow classmates. He was always so responsive to questions and messages despite him having a heavier schedule than most. He has inspired me so much about selflessness and putting others before yourself. I hope to follow in his steps one day to also become a TA for a class (maybe this class) because he was so so so amazing. I have nothing but praise for Ivan."
  • "The TA was probably the best teacher that I have had out of all of my teachers at Penn. He went out of his way to help us, and even held 2.5 hour Friday review sessions every single week to go over the weekly lectures, in addition to his recitation. He also compiled an entire book of notes for his students, which have been extremely useful. He also created a piazza page and answered any question that we had about the course within 20 minutes of asking. He made math fun, and he actually cared about whether or not we learned something."
  • "Ivan was the only reason that I passed Math 114. His review sessions were so incredibly helpful, and he was always willing to explain topics no matter how many times I asked. He also had an extremely active Piazza page that he used to answer questions even when he wasn't in office hours. The only reason I feel confident taking Math 240 is because Ivan is planning to TA that class."
  • "The best TA out there, I think everyone will agree. Thank you Ivan! As someone who wants to be an educator myself, I have the utmost respect for your style and just genuine interest in your students' success. It's a rare skill and a rare passion. I wish you all the best! I hope my comments are helpful in any way."
  • "Ivan Li was the only reason that the course was manageable for most students. He gave up a lot of his own time and effort outside of recitation (holding extended office hours, having extra lectures of his own, answering emails and piazza questions) to make up for the lack of instruction by the professor."
  • "The TA essentially taught this class as lecture was useless. James Haglund would use Rimmer's Powerpoint slides that he had never seen before until that day, and was ineffective at communicating the course material. Many things on the final exam Haglund never discussed. Yilun is the only reason many students learned anything in this class."
  • "Ivan taught much better and much more successfully than the actual professor. If Ivan was the professor the class would actually learn material."
  • "Ivan is the best TA you'll ever have. Seriously he does so much for his kids. If you have him, it doesn't matter how difficult the class or teacher is. He'll help you enough."
  • "Ivan Li is probably the best TA that has ever existed and is the only reason I learned anything in this class."
  • "Ivan Li is the greatest TA in the history of humanity. Never in my life have I ever seen someone who has gone above and beyond the call of duty in any endeavor like Ivan Li. To begin, Ivan began doing optional shadow lectures of Haglund on Fridays, where he would review the entire week's materials. Second, his website posts so much relevant information and resources. His LaTex notes document, which is over 100 pages long, was more helpful in this course that Haglund's lectures, MyMathLab, AND the Godzilla textbook combined. I cannot even express how amazed I am by Ivan. I would take a course just because he is TAing it. I propose that the Math Department starts an annual award for the Best TA, and name it the Ivan Li award, because he deserves it. If only all TAs were like Ivan........."
  • "Ivan went above and beyond in all aspects of being a TA. Don't think I would have gotten the grade I did without him and I'm grateful. Overall, best TA."
  • "Despite the poor quality of the lecture, Yilun went above and beyond to help out each and every student, including those who were not even assigned to his recitations. When he saw students struggling and giving up on the main lecture, he hosted a three hour review and teaching session each week and recorded it for students who could not make it in order to ensure that we would all be prepared for each final and midterm. He was incredibly accessible and quick to answer emails and Piazza questions. Additionally, he worked incredibly hard to grade each of our exams and return them to us with impressive expedience."
  • "The TA was extremely devoted to finding every opportunity to help students, ranging from helpful Friday review sessions basically every week to a piazza page, and honestly was such a far better "teacher" than the professor that lecture was almost awkward seeing how poorly the professor taught the course as compared to a TA who is simply another college student."
  • "This is the best TA at Penn. He goes the extra mile every week and was fantastic at explaining the concepts of multi. I think I would have failed without his help. Give this man a raise!"
  • "Yilun is committed to make every student who shows up to his recitation to understand and know the material. He puts in a lot of effort in providing examples that he believes will make us understand chapters a lot better. I would also say he explains things in a straight forward manner which is great because the textbook can get very confusing when it is hard to physically grasp what it is saying. Overall, I would say he is the best TA you could get!"
  • "Ivan is absolutely the best TA/instructor in math that I have ever had. He is consistently available to answer student questions on Piazza even with his busy schedule and is genuinely concerned with helping his students succeed. For example, he held extra Friday review sessions almost every week in the semester to help students practice things that they could not pick up in lecture. If not for Ivan , this course would have been much much harder."
  • "Ivan was the best TA I've had. If it wasn't for him I would have dropped the class!"
  • "Ivan was single-handedly the reason why I did not do poorly in this class. He made the material more interesting and gave students of the class many opportunities to meet with him to clear up any difficulties. He went above and beyond in all respects."
  • "Ivan is actually the best. He has been committed to making sure we learn the material before the Final. He worked out what he should go through in the recitations to make sure we have plenty of time to study for the final. He even had make-up lectures on Friday afternoons to teach us the material since Haglund's style didn't work. Highly recommend him, so honored to be so pampered my freshman year."
  • "Ivan is an incredible TA that cares about his students and is dedicated to their learning. I passed this class only because of his help. He held regular office hours and review sessions which helped me grasp material that I could not understand in lecture due to a poor professor. Ivan really has a great skill in teaching and catering to the needs of his students. The math department is lucky to have him as a TA."
  • "Ivan was basically the professor of this course. He hosted regular weekly extra review sessions to supplement the lectures and recitations. His website compiled personal notes for every section of every unit and presented numerous problems from past finals and midterms for review. Somehow he managed to function as basically a full-time math teacher while being a Junior dual-degree student."

Spring 2017 - Math 114 (Hablicsek) - Won TA Award ~70 Students

TA Quality: 3.76/4.00 - Highest 114 rating ever on Penncoursereview

  • "Ivan was an amazing TA. Sometimes he taught the material better than the professor. I am very lucky to have had him for the course."
  • "I was at times frustrated that Prof Hablicsek didn't post any notes online. It was difficult to rely exclusively on Rimmer's notes when studying. Ivan was amazing, seriously so good."
  • "Absolutely amazing TA. Really helped solidify my understanding of the material."
  • "Ivan was incredible as a TA. He seemed very passionate about math. Not only that he seemed very passionate about helping learn so that we could develop the level of knowledge he had about Math. Overall, he was an A+ TA."
  • "IVAN IS THE MOST AWESOME TA I'VE EVER MET. He is accountable, easy to reach out, friendly and even very fast in scoring. He is very clear when teaching materials for 114!!"
  • "Awesome TA! Really knew what he was talking about and was friendly and highly available via both emails and office hours."
  • "Ivan is the best TA I've had during my time at Penn in any class."
  • "Ivan is the only reason I know anything about 114 he is literally a godsend 1000% would recommend him"
  • "Absolutely amazing TA! So accessible, patient, and helpful. Taught me everything I know about math 114. Much more helpful than the professor himself. Would recommend Ivan (Yilun) as a TA to anyone."
  • "Ivan's website and many many resources truly helped me learn calculus! His email responses were always extremely fast, and he held many office hours and review sessions for us. An amazing TA!! Would not have learned calculus without his help!"
  • "Without the help of the TA, I probably would have done much worse on exams and would have a weaker grasp on the content. The TA really knows how to explain the content well and answers questions appropriately. A very great job in helping students and being an important resource for them."
  • "should win math ta award if there was one..."

Fall 2016 - Math 114 (Alexandersson) ~70 students

TA Quality: 3.56/4.00

  • "BEST TA EVER!! Ivan is super helpful when it comes to learning the material and always goes the extra mile to make sure students understand."
  • "Most amazing TA I've had or could ever imagine having. Explained hard concepts to me in ways that made sense, was a great role model, and always made time for his students. Would not have understood the course material nearly as well without him."
  • "Phenomenal TA. Always available to answer my questions and did a much better job at explaining the material than the teacher. Highly recommend!"
  • "Ivan was an amazing TA. He is so intelligent and can answer questions VERY clearly. I cannot imagine having had a better TA. He gives not just amazing math advice but also general guidance on college and majors. Wonderful."
  • "Ivan is a fantastic TA who is able to understand a student's perspective and answer questions/teach material accordingly. He was very accessible outside of class and responded to emails very quickly. His recitations were useful for understanding the material better. I have no complaints."
  • "Ivan helped me so much in this class. Sometimes it felt like recitation taught me more than lecture."