In teaching, less is more


Question: When you’re teaching, how much should you cover?

I propose a couple answers:

Answer A: You shouldn’t cover much, because the more you cover, the less they learn.

Answer B: Trick question! You’re not supposed to “cover” anything! If you teach a topic by just making sure it gets covered in a lecture, then you’re not really teaching it.

Imagine your goal is to teach just one relatively narrow topic for the entire semester. For example, let’s say you had a whole semester on understanding how a Mammalian Kidney works. At the end of the semester, you should have a high level of confidence that the students in the class know about kidneys. After all, you spent a lot of time thinking, discussing, writing, drawing, solving problems and such about kidneys.

Now, imagine the opposite: your goal is to cover Animal and Plant Biodiversity, including the structure and function of major anatomical features. (This includes the mammalian kidney.)

Clearly, in the latter example, the students will know less about the kidney. But let me ask you another question: Which of those two courses resulted, overall, in more learning? Imagine tracking down students from both these classes, five years after they took the final exam, and evaluating how much they learned.

I would bet you a medium cappuccino that the student in the Mammalian Kidney course remembered more about the kidney than the student in the Animal and Plant Biodiversity course learned about biodiversity. Why do I think that? Because the kidney course would give you the chance to think hard and critically about something. But a course about all of life, at least the way I think it is often taught, is skimming the surface of everything.  Some departments will call such a curriculum a “March of the Phyla.*” When you’re marching through a lot of territory, you’re not going to remember it all that well.

How well you learn something is a function of how much time you spend on it, and also how you are going about learning. Learning through inquiry, using a variety of approaches that some put under the umbrella term “active learning,” is simply more effective than lecturing.

One of the most common arguments for (or perhaps, defenses of) the lecture is that you can cover a lot more material. There just isn’t time for active learning approaches, supposedly, because you’re required to have the students learn so much more at the end of the semester. While it is true that you can’t cover as many topics in 45 contact hours using active learning compared to lecturing, I’m not convinced that this means that students will learn less. It just means you cover less. Because covering something ≠ learning something. And memorizing something enough to do well on an exam ≠ learning something.

Covering something for the sake of covering it is pointless. Having a student be introduced to the concept of something, but not taking the time to actually support learning, rarely does anybody a useful service.

And here’s an idea: When you learn a few things in depth, then this might support better learning of things that you choose to not mention!

When I approach a new class (which admittedly, hasn’t happened for a good long while, and I’m on sabbatical now), I count up the number of hours that we have in class session. And then, I come up with that number of fundamental facts, concepts and ideas that encapsulate the course. This is not an easy thing to do. The way I do this is to ask myself, “Five years from now, what are the 40 most fundamental things that I want students take away from this class?” And then, when I teach the lesson, I’m doing it thinking about whether we’re doing it in a way that will still be memorable five years into the future.

How do I do that? Well, people are a lot more likely to remember experiences. People remember when they discover things on their own. They don’t remember things when they are told about them. So, I design lessons with the notion that students will develop and discuss and figure out ideas on their own, rather than me telling them about it.

This means that we don’t really cover that much material at all in class, compared to a stereotypical lecture course covering the same topic. But who learned more at the end of the semester, and after five years?

So let’s imagine a course about Animal and Plant Biodiversity, Structure and Function. The March of the Phyla. How could you possibly just narrow it down to 40 fundamental facts and ideas, each of which can be addressed with an active lesson in the course of an hour? That sounds hard! And it is. What’s harder, though, is coming up with 3000 facts, cramming them into 40 hours of lecture, and expecting anybody to genuinely learn.

I think this approach works beyond what happens in the classroom. If you’re doing more inquiry and interactive work during class sessions, then I imagine that students will be more engaged when they’re reading of the textbook and working on assignments. If the lecture is genuinely engaging, that engagement is more likely to transfer to material that is part of the course learning objectives but not covered in the lessons in class. It’s okay to require students to know some things from a textbook without having it part of a detailed lesson (as long as you do it in a fair manner), and actually narrowing down what you do in class might increase the total amount of material that students engage with in a constructive manner.

Where is this, possibly, the biggest challenge? I imagine it’s when you’re expected to teach to a set curriculum that you have limited control over. For example, some contingent faculty and instructors in a situation with multiple sections might be in this boat. Also, I’ve heard more than once that accreditation means that the amount of content and the approach to teaching must be highly standardized, for example, with respect to ACS accreditation in Chemistry. But gosh, when I read the ACS accreditation guidelines, this doesn’t seem to be the case: “The diversity of institutions and students requires a variety of approaches for teaching general or introductory chemistry.” The prescribed number of topics and the things that you need to learn in labs is very sensible and allows for a ton of flexibility. ACS clearly doesn’t expect everybody to teach chemistry the same way. So, yeah, I think accreditation has its pluses and doesn’t have to constrain you too much.

It should still be around the start of your semester – if you’re daunted by the breadth of your syllabus, it’s not too late to shoot for depth instead.



*Apparently this term was used, and perhaps coined, in the title of an essay by Isaac Asimov.

9 thoughts on “In teaching, less is more

  1. You’re probably right about who will remember more from an individual class five years later. My concern is who will remember what they need to pass pathophysiology next semester, and the rest of their nursing courses – in which they will be reminded of, and using information about, all the body systems I covered. I don’t have the option of focusing on just a few systems. So the challenge becomes to ‘cover’ all the systems in a more effective way than merely mentioning them in lecture, and in ways that address different students’ learning styles.

  2. These are very good points to consider!
    I am teaching my own class for the very first time ever…4th year animal behaviour.
    I have made what I think is a modest syllabus (we spend 2h/week in lab and 2h/week in class), but even now it feels like I am not doing a good job engaging the students during class time.
    Our lab is fundamentally active learning (it is hands-on and participatory), but with just 2 hours it needs to be somewhat scripted and managed. I do feel good about it though, as when the animals are behaving, and Catherine and I are circulating and helping with observation, it feels almost like taking students into the field. I just need to figure out a way to get the students to take ownership of the experiments!!! We do have 2 lab periods that are labelled “open” and part of their work is to pitch what we should do with this time, be it revisiting a previous experiment, or something entirely new).
    Anyway, I am keeping good track of what is going on, and hoping this will be a good learning experience for us all!

  3. bowneps, just wanted to give a plug for the idea that the idea that students have learning styles isn’t really supported by data. Some students might prefer one medium or approach over another (some prefer to watch and not read, some prefer to talk and not write), but there’s no research to show that learning styles is actually a thing.

  4. My father used to say that every lesson is too short from the teacher’s point of view, and too long from the learner’s. I think one reason this happens is that we don’t have formative assessments in class to give us an accurate idea of how well learners are absorbing information – if we had that feedback in real time, I think we’d better realize how often we’re teaching at the speed we can talk, rather than the speed people can learn.

  5. Not that I’ll ever teach a “March of the Phyla” class, but I feel like a fun semester-long active learning assignment would be for students to pick a species from the major phyla and ask them to document what they all have in common (& what is obviously quite different).

  6. I think you’re right but of course there is always nuance and the truth is often a balancing act. I teach General Chemistry and in addition to ACS accreditation guidelines, there is also the fact that the Organic Chemistry instructors will be pretty upset if I don’t cover certain topics (mostly orbitals, polarity, acid-base equilibrium).

    I think it does depend also on the purpose of the course. A lot of times, it seems to me, the purpose of the freshman “general” or overview courses are not “learning” per se but rather to give the students a broad exposure to the field, familiarity (but not necessarily fluency) with the vocabulary of the field, and some good study skills. The subsequent topical course then dive into more actual learning as you are describing.

    In the end, I totally agree that when we lecture it is easy to assume learning is happening but active learning helps assess how much our students are likely actually learning.

  7. I will just say: great article, also from an ESOL English teacher point of view (one under constant pressure/curse to “cover enough” … i.e. too much, and therefore not enough.

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