This year I’m trying out a flipped classroom while teaching Linear Algebra. I’m using the ABC Model developed by David Pengelley. His webpage seems to be down at the moment, but he wrote an excellent article for the AMS Notices describing his method. Basically, the idea is to get the students to read the textbook as their first contact with the material, rather than lecture to them. Homework consists of three parts:
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- Part A: Students do a reading, and respond to reading questions I have written for that section. The reading questions are supposed to ensure that students think about key concepts and pay attention to subtleties. Students also respond to reflection questions. These are turned in online via a Google form the day before class.
- Part B: Students do about 10 warm-up problems for each class period. I grade these during class based entirely on completion; the students either have given them a try or not. Most of the class period is spent with students discussing these problems in groups.
- Part C: Students do 2 more challenging problems and turn them in the next class period. This are usually not computation-based, and receive thorough feedback from me.

Class time at the moment tends to follow this schedule: We begin with a discussion of the reading questions, where I select students who had especially good answers to present to the class. I ran into a problem where students didn’t realize I was curating these answers, and had to let them know that I was only calling on people who had correct solutions! After this, I may spend some time clearing up common misconceptions and/or responding to questions from the reflections. This usually takes a total of 15-20 minutes. Then the students work in groups, and I circulate. As I go through the room, I check in everyone’s Part B work, turn back the Part C homework from the previous class, and ask if they have questions for me. This is my chance to interact with each student individually, and I’m not sure that I use it to my best advantage. During this process, I may put some problems on the board for students to write their solutions. These students then explain their solutions to the class. This continues to the end of the period.
What’s Going Well
What students seem to like most about this style of course is that it gives me more time to interact directly with them and answer their questions. When asked “What are three things the instructor does well to aid in your learning,” the most common themes were:
- Answers questions in class and responds to our answers in the reading questions
- Great enthusiasm
- Good explanations of harder concepts
- Focusing on conceptual issues in class
Students are working really well in groups. They have organically formed groups of about 3 students each, and they do a good job spending their time checking their work, helping each other, and collaborating on harder problems. As I walk around the room, I see them discussing possible solutions and explaining errors. I hear a lot of, “I see, I made an error in this step and that’s how I got the wrong answer.” I love that they are identifying their own mistakes.
So far, getting everyone involved has not been much of a challenge. I’m keeping track of who writes solutions on the board and ensuring that everyone does so pretty evenly, by recruiting presenters when needed. I use a color-coded spreadsheet to mark attendance, who answers reading questions, and who presents at the board.

Students mostly felt that they could participate easily in class, though 2/3 of them have expressed concerns about appearing stupid in front of their classmates. I staged in intervention with my students, where I told them that fact, and also shared that about 90% of math grad students at UChicago feel “inadequate in relation to their research.” I also told them about times that I have failed and felt stupid, and expressed the hope that this class can become a space where they learn to feel comfortable saying that they don’t know the answer. We’ll have to see if that makes a difference in their willingness to be show their confusion, or risk making a mistake.

Additionally, I think the students are learning the material pretty well. They do a universally good job of answering the reading questions, and they all seem to be conversant in the relevant vocabulary. One benefit of this system is that we are on a schedule, and at no risk of falling behind. My friend who is teaching the same class as me is about a week behind in terms of content. So far, everyone is doing well on their homework and I haven’t noticed anybody who is just totally lost. This makes me feel pretty good!
What Could be Improved, and How I’ll Do It
My biggest issue with this structure is that about half the students don’t really like it. Part of that does seem to be that it is harder to “coast” to a good grade. Students complain that we’re covering a lot of content, but I’m not covering more than what we are told to do. I think that other teachers end up cutting material that they don’t have time to cover, so perhaps my students will actually learn more content than their peers. But mostly, I think it just feels like more content because they aren’t zoning out during lectures. The amount of time the students report doing the reading is (on average) less than a class period. Students have said things like, “I think lectures make slightly more sense with regards to math because it is a more difficult subject.” I tend to think that even if math is a more difficult subject, that would make it a good place to apply a seminar/flipped learning style.
I’ve also had students tell me that they hoped I would lecture in class, because I’m very good at it! That people who are bad at lecturing should teach like this. I don’t really know what to think about that. On one hand, I think people should play to their strengths in teaching. On the other hand, I suspect that most bad lecturers would also be bad in a flipped classroom.
My planned solution is to be a bit more systematic in my talks at the beginning of class. I still won’t give definitions or theorems, but I’ll try to help them organize the material and relate the new material to older content. I want students to get first contact with the material through reading the textbook, not through lecture. So i don’t want my in-class talks to allow them to skimp on the reading. Luckily I’ll still have reading questions to keep them honest, and I think that if my “lecture” serves more to organize material than it does to explain or introduce it, then I’ll be helping with something the textbook isn’t as good at. Hopefully that will be enough to scratch that lecture itch for most of my students.

Another fear that I have is that, even though I am interacting more with students in this style of classroom than I would in a lecture, I am less aware of how well my students will do on the midterm now than I was in any of my previous classes. This is because in previous classes, I have used oodles and oodles of Classroom Assessment Techniques (CATs), to keep track of how the students are doing, and to give the students a heads up on how they are doing. In a single lecture, I might have three mini-quizzes for students to practice their problem solving, and to give me information on what the class does and does not understand. I don’t have that now; since each problem is only presented by a single student, all I know is that at least one of my students knows how to solve it. And while students are doing well on the homework so far, that only tells me that their group work is really paying off. I have no idea what will happen when they have to work alone on an exam.
While I love reading the responses to the reflection questions, and sometimes get surprisingly self-aware replies (“I am learning more in this class that in a more tradition lecture, but maybe that’s just because I’m working harder.”), I don’t know how much I can trust their self-assessment of their own knowledge. The Dunning-Kroger Effect famously shows that there is an overlap in knowledge required to do a task and to assess how well you did that task, so people who are struggling are less likely to be aware that they are struggling.
My solution is that I will simply ask them to spend time in class doing little CAT quizzes. I’ll decrease the number of warm up problems, and use some of the problems I would have assigned in the quiz instead. There’s no reason not to do this, except that I need to work out how best to fit this into the flow of the class. I think the best bet is to do it in the last five minutes of class, after they’ve had a chance to work on some problems with their peers and ask me questions.
Finally, the students are 50/50 on whether they like the textbook or think it is awful. My own feelings about the textbook are equally mixed. While I have already listed some resources, I know that students are not using them regularly.
My solution for now will be to make alternative resources for certain topics more obvious, perhaps by linking directly to the relevant Khan Academy video (or similar). I think the best solution in the future would be to carefully curate each section’s resource, and provide one or two quality alternatives. The downside to this is that there are a lot of resources out there, and finding the “best” one is going to be a lot of work. But then again, if I’m expecting a lot of work from my students it’s only fair that I do the same.









On Thursday, I finally got a chance to see Hamilton, the hit musical by Lin-Manuel Miranda. Overall, it lived up to the hype – which is a significant accomplishment! I enjoyed the music more than I expected, and loved how intricate the text could be because of the freedom of rap. Wayne Brady performed as Aaron Burr – a surprising choice that ended up working incredibly well. The best thing about the libretto is the depth of Alexander Hamilton and Aaron Burr. While Hamilton is of course the hero of the story, we are shown some of his flaws: hot-headedness, arrogance, limitless appetite. Similarly, the supposed villain of the show, Aaron Burr, is presented as a Salieri-esque character, a la Amadeus. He was meant to be a success, but was overshadowed by a younger, more brilliant replacement before he ever got to make his mark. It’s an interesting contrast in today’s political climate as well – the man with strong principles who is unwilling to compromise for political advantage, versus the man who compromises so much that his beliefs are unknown.







