What makes a good teacher? I am sure that people who work in education have precise metrics for what effective teaching means.

I am not an education scholar, but I do teach, so doing it well is important to me (and to most of the readership, I am sure). I am at a research university, which means that teaching is an important aspect, but also one that is secondary to research. It is not faculty who unilaterally decide to focus on research. The prestige and grant funding that come from research are what drives this emphasis, which is enthusiastically endorsed by university administration.

In my view, there are roughly three important facets of traditional teaching. The performance art of teaching, the 1-1 or small-group interactions with students (discussions, office hours, emails), and the course materials (including exams).

The performance art of teaching: being “good in the classroom,” being charming and engaging. Being able to convey your knowledge clearly and effectively. At research universities, some of the best in-class teachers-performers are indeed the well-funded and successful researchers. This should come as no surprise, as the ability to explain and engage are as important when impressing panel reviewers as they are when trying to animate sleepy undergrads in a required freshman course. Being an interesting lecturer correlates strongly with good teaching evaluations: students highly value being engaged. This aspect of teaching is also one that comes much more easily to some faculty than others; for those who are naturally charismatic presenters, it doesn’t take much time or effort to mesmerize the crowd.

The second part are 1-on-1 or small-group interactions. The flipped classroom strives to eliminate the lecture in favor of small-group interactions that follow out-of-class viewing of videos. In a traditional classroom, these may be office hours or a discussion section. Few-people interactions are very beneficial to student learning, but many students don’t take advantage of them. Holding frequent office hours, for instance, where only 1-2 students show up, requires a lot of professorial time, but likely has a very small effect on teaching evaluations, even though it helps a lot to those who show up. Also, spending a lot of time on email is one of those things that everyone expects, so you will likely be penalized in evaluations if you don’t do it, but won’t be praised if you do. Gotta love the thankless effort.

Finally, there are the course materials. In my opinion, good course materials (I include exams in this category, as a good exam is not just a test but an education opportunity) are critical for student learning and require considerable time to create. These days, many people teach with PPT slides. It works for some, perhaps many people, so kudos to the readers for whom it does. I appreciate that PPTs take a ton of time to make, so the effort is not lost on me. But I have always hated PPT lectures as a student, as they made me fall asleep. The teachers who worked with PPTs alone generally didn’t move from the lectern, which further made everything more static and my narcoleptic self would just doze off. Good homework assignments and projects (and their equivalents in the humanities), which  really bring key concepts into focus and enforce what was done in class, are hard to develop. In my view, this is exactly the most important part of learning for the students, because they don’t really retain anything until they try to apply what they think they grasped in lecture to actual concrete problems. That’s where they see they didn’t get all they thought they got. However, copious or difficult materials that really lead to learning are not necessarily widely appreciated by students, especially not in the short term, i.e. not on the time scales relevant for student evaluations.

Some of the best lecturers I have had didn’t end up teaching me much in the long run. The lectures were breezy and fun, but the breeze and fun came at the cost of rigor and substance. On the other hand, some of the people that I learned the most from were pretty boring in the classroom, but the materials that we had to go through really did it for me and made me learn. Of course, it is quite possible and perhaps not even rare to have a teacher who is both charismatic in the classroom and a master project/homework creator. My absolutely best teacher ever was the author of a beloved textbook classic, magnificent in the classroom (not what you would call charismatic, but still strangely captivating), and giving the best, most interesting exams I have ever had in my life — they profoundly affected how I design my exams these days. I remember loving his courses and looking forward to his brain-teasing tests; most of the graduate student populace dreaded them as tricky.

Sometimes people say that great teaching doesn’t require a lot of time. I would say that great lecturing probably doesn’t require a lot of time. I am the first to say that I can work an undergraduate classroom quite effectively with very minimal preparation. While a traditional lecture with an enticing teacher is where interest might be sparked, learning doesn’t happen until the students themselves do the work.

My best teacher ever said that 20% of the students will do well no matter how poorly you teach, 20% will do poorly no matter how well you teach, and there is the middle 60% where your teaching can make a difference, so they are the ones we should be teaching to. Based on my experience, a good teacher inspires a student to want to put in the work and learn; a great teacher organizes the course and makes the materials such that even the students who are not inspired end up learning the essentials, in spite of themselves.