Here are a few difficult facts about education in college classrooms:

Lectures don’t work well. People just don’t really learn much from hour-long lectures. People learn when they discover ideas on their own. People learn best when working with peers. It’s a hell of a lot easier to just explain something to someone than to set up a situation in which this person can figure it out for themselves It takes a lot longer for a person to figure something out than it takes for you to just explain it to them.

I suppose you can take issue with some of these facts and argue that they’re not true facts. But just as climate scientists are mighty darn sure about anthropogenic warming trends, education researchers seem to be just as sure about this these facts. I let them take my word for it about ecology and evolution, and I’ll take their word for it about education.

And this is a problem, because it means that what a lot of us have been doing appears to not just suboptimal but downright inadvisable. For example, about ten years ago, I subbed for a colleague’s Conservation Biology’s course. She gave me her notes for the day, as she had taught it in previous semesters. I tried to lecture as quickly as possible, but I only got through about a quarter of the material that she usually taught in a single period. The only way she could have taught this much information would have been to talk extremely quickly, with students transcribing without really thinking. What are the odds that the students really learned something that day? I’d say somewhere between nil and none.

If we are going to design lessons in which students genuinely learn in class, that means that we need to seriously pare back on the number of facts and concepts that we are going to address in a class session. Which means paring back the total number of concepts for the whole semester. We are in love with the cool little details. Who doesn’t want to lecture for ten minutes on the extraordinarily long penises of barnacles or the likelihood that carnivorous kangaroos once prowled the plains of Antarctica? Lecturing on cool stuff is fun, but if we do more than just a little of it, then we actually are depriving our students of the opportunity to learn in the limited time we have with them, typically just 45 hours for a full lecture course.

Here are a few difficult facts about my job as a professor:

The professional and personal development of students is my highest priority at work. Classroom teaching is only one part of my job. Research is important and a high priority. If I spend all of my time teaching, I’ll have no time for research and mentorship. If I don’t spend enough time writing papers and grants, I lose resources to do research with students.

I want to design my classes for students to learn, but I can’t spend too much time teaching. Which means that somehow I need to find a way to teach efficiently – to be as effective as I can given the amount of time I can give to the teaching assignment. There are so many ways of teaching. Some are more effective for the students, and some are more time efficient for the instructor. I’m focused on finding that sweet spot where I can be an effective instructor without losing all of my working hours on a class. Or, as the title of a well-used book among K-12 teachers says, Never Work Harder Than Your Students.

Common wisdom is that it takes less time to prepare lectures than it takes to develop an inquiry-based lesson. I’m not sure I agree with this. At least, I think the lessons that I’ve been teaching haven’t taken any more time than it would take me to put together a pretty good lecture. So, then, what is it that I do in my inquiry-based, group-working classes that doesn’t take so much prep time? I’ll walk through some ways I’ve put a lesson together.

My big challenge in creating an active-learning lesson is not to decide what to teach but what to not teach. I think there’s a huge hurdle to get over, or a big concept to get one’s mind around, in the process of choosing against the lecture. I realized that I’ve just got to let content go. There is information that I love to share, but I don’t include it in my lessons because we just don’t have the time and they end up being not as relevant to the central concept. A cliché in education — that less is more — seems to be true. If you give students a few key concepts to learn about in class, and they learn these concepts really well while working together, then they are going to learn far more content overall, through exposure to reading and other assignments. Just because I didn’t take 20 minutes to explain the subtle details of Connell’s barnacle competition experiment doesn’t mean that students won’t learn about it. But if the students take a whole hour to discover principles about competition on their own in class, then they’ll be able to really appreciate the Connell experiment when they read the chapter. It seems counter-intuitive, but I’ve discovered (for myself) that it’s true. But hopefully I’ve arranged the situation for you to discover this for yourself if you decide to teach without a lecture, pare back on content, and discover that students learn more detail in the long run.

Consequently, when I teach a lesson, I need to decide for a whole hour, what central concept matters. And it’s a really simple one. For example, what is the central limit theorem? Once I get a handle on a single concept, I need to come up with a set of activities for students to do together in groups to figure out the central concept on their own. What do those activities look like? It can be a huge variety of things. My general principle is that it should never involve me standing at the front of the room talking for more than five minutes at the time, and that the bulk of the time is students actively working together on something built towards creating their own understanding of the central idea.

In my central limit theorem lesson, I bring a bunch of dice to the class. I ask the students to quickly draw a distribution of expected frequencies if they roll one die at a time – the odds of getting any number 1-6 are equal to one another. I then ask them to calculate the odds of the outcomes by rolling two dice and adding the numbers together, with the odds of getting values between 2 and 12. I don’t call out to the class for raised hands – I ask the students to work together for a couple minutes and then ask some groups to share out. I summarize this quickly on the board. I then ask the groups to come up with their predictions about how the shape of the frequency distribution might change based on the number of dice they roll. What would it look like after just a few rolls? How about 15? How about 30? How about 100? Unless some students have read further ahead in the book than I expect, there ends up being a broad range of predictions, and in my experience, few of those predictions are actually correct. Then, I ask the students to build their own frequency histograms by rolling the dice. A lot. Then I get each group to plot its distributions on the board (or if I were in “brilliant” classroom we could do this other ways, though I think I’d like the board just as much.) That dice rolling and data management takes at least half an hour. Then, I ask the students to compare their findings to their predictions. Once we put everybody’s findings together, and groups mill around to visit with neighboring groups, then people figure out how the distribution changes as they roll more dice. Then, as the class is winding down, I go to a website that does virtual dice rolls to cement the discovery, and we spend a few minutes talking about how the central limit theorem seems counterintuitive but indeed that’s the math and the probabilities work. And that this is a central concept for all (frequentist) statistics.

How would I teach the central limit theorem as a lecture? I guess I’d explain it verbally, and show a variety of powerpoint slides with a few examples, and then show to the class the virtual dice rolls. And I’d be able to cover a lot more material in the same period of time. But what’s more important: covering material, or allowing the students to learn by finding out the idea on their own? I would bet, or at least hope, that students in my inquiry-based lesson will remember the central limit theorem a few years later based on our dice rolling session. At least, I have a half of a chance that they might. But would they remember a five-minute lecture? No way. I don’t design my classes for the exam, I design them for the long haul. And I’m betting that a deeper understanding of the central limit theorem results in better mastery of statistics, and a better ability of the student to follow the textbook, than a high quality lecture. And if any student wants a lecture, they can always hit up the internet, where they can find a lecture as good or better than one that I would be able to cook up.

How do I teach other kinds of topics using group work and active learning approaches? It depends on what the central concept is. While rolling dice allows students to actually observe a mathematical phenomenon, students can’t readily observe and solve problems involving things like island biogeography or natural selection. In these situations, I’m more inclined to present problems or case scenarios, either real ones from the literature or something that I just make up. I then ask the students to develop ideas that can explain something, or to develop predictions. I then provide additional information as they work on the problem.

For example, the last time I taught a lesson on natural selection, I handed out to everybody in class a few summary pages from Malthus’s Essay on the Principle of Population. I gave them 10 minutes, right on the spot, to read those pages, and I was there to answer vocab and language questions. I then asked them in small groups to why they thought that this was one of the essential pieces of writing that independently influenced Wallace and Darwin as they figured out natural selection more than fifty years later. I asked them how this information from Malthus fits in with the “struggle for existence” in organisms. I then tell them that another commonality among Darwin and Wallace is that they both had the epiphany that every species has inherent variation among individuals that isn’t a flaw but instead reflects traits that are passed on from generation to generation. With groups of four students working together, I ask them to develop a line of argument to understand how “decent with modification” can happen. With some leading questions, with some groups needing a little more prodding (or the opportunity to consult with neighboring groups), the students pretty much independently derive something similar to Ernst Mayr’s classic distillation of Darwin’s summary of the argument for natural selection. Here’s the thing: the groups do this without me ever telling them how natural selection works, until the lesson is over and (most) students have already done it on their own. It takes a whole hour, or sometimes a little more, to go through this process. In contrast, a lecture about the specific mechanism of natural selection would take five minutes, with all kinds of specific examples. But I’d rather give the students an hour to figure out natural selection on their own, in a closely guided fashion, instead of just being told. I think the odds that they’ll remember it, and be able to explain it to others, is a lot greater. That’s what the education researchers tell me at least.

Coming up with a lesson like that is not necessarily more work for me than lecturing. It actually seems easier to me. We all have gotten lectures on so many different topics as students, that we know how to put together a solid lecture as instructors. But few of us have experienced inquiry-focused lessons (other than laboratories), and the lack of familiarity might make it seem harder. But if you give it a try, I suspect ain’t so hard. Another nice thing about dropping lectures is that it frees me from having to stand up in front of a class and speak so much, and I get to mill around a classroom and listen to groups working.

One thing to keep in mind is that for untenured faculty, that the quality of your teaching and student learning plays little to no role in your tenure case, even if you’re at a teaching institution. Instead, what matters is the perception of teaching effectiveness, in the eyes of those who are evaluating your tenure case. For example, in my last job I was advised to “be less Socratic and lecture more.” In that department, active learning strategies were unacceptable. So, if you choose to teach in a matter that is markedly different than your colleagues, then it’s advisable to consult with a trusted senior faculty member before rocking the boat. But if you’re tenured, heck I say rock the boat! That’s what tenure is for, don’t waste it!