I have bias, but deep down I know the truth: it’s not about me, it’s about the science — and there’s more science to do.

I have personally been tempted to dismiss “active learning” as hype — as a pedagogical fad that should have died as quickly as NFTs. But it turns out I’ve (unintentionally?) adopted active learning in my own classes, which reach as many as 1000 students per year. Why the temptation, and why the adoption? Let me tell you.

I Have Bias

As a high school student (ca. 1991–5) and college student (ca. 1995–9) and graduate student taking classes (ca. 2000–5), I experienced traditional lectures: the big STEM lecture-hall lectures in which the professor talked for an hour and I took notes. I succeeded academically during that time. That trained me to believe that traditional lecture was working as it should. Why would I depart from the educational structure that previously benefited me?

As a professor (ca. 2011–present), I have been responsible for teaching ever-larger classes. Traditional lecture scales well with a single instructor and many (10, 100, 1000…) students. It can be done adequately — with manageable prep time — by most faculty who have chosen the career. Why would I depart from the educational structure that now benefits me?

As a skeptical human (ca. 1977–present), I am averse to sales jobs. In my experience, active-learning evangelists can be so enthusiastic as to trigger that aversion.

But Deep Down I Know the Truth

As a Trained Scientist™️, I do my best to be open to new ideas but evaluate them rigorously. Also as a scientist, I recognize that I am a biased sample: I am the student who became faculty. Most of my students will not do the same. What worked for me will not necessarily work for them. Maybe it didn’t even work that well for me…?

• I admit I struggled through traditional lecture. There were days I couldn’t keep up, days I got lost, days I fell asleep. That despite being gifted with some great teachers who were giving well-prepared, well-delivered traditional lectures.
• I acknowledge I didn’t truly master the content of any class because of traditional lecture. I mastered it when I repeatedly applied it, especially when the application was teaching it to peers and later to my students.

Traditional lecture was the gateway, not the final destination. But why make any changes to that gateway?

It’s Not About Me, It’s About the Science

We need technically literate citizens with complex problem-solving skills. [We need] to make science education effective and relevant for a large and necessarily more diverse fraction of the population. –Carl Weiman (Nobel Prize winner)

So let’s go meta: what does science say about science education? In meta-analyses of hundreds of active-learning studies (Freeman et al. 2014, Theobald et al. 2020), the benefits of active learning are compelling to this skeptic:

• Active learning increases performance by 1/3 letter grade over traditional lecture.
• Students in traditional-lecture courses are 1.5x more likely to fail than in active-learning courses.
• Active learning reduces achievement gaps by 33–45% for underrepresented students.
• The effects occur across STEM fields: biology, chemistry, computer science, engineering, geology, math, physics, and psychology.

If your jaw didn’t just drop, then go back and read that list again.

Really; I’ll wait. 😀

Perhaps this is the point where your own skepticism or aversion to sales jobs is kicking in. You might have objections or questions. I know I did!

Rather than channel the authors myself, let me suggest that you read those meta-analyses and see how they clear up all doubts. Except for a really big one that I’ll save until the end of this post…

You can also go back to the original studies cited in the meta-analyses. Individually those might be less compelling. After all, when it was a just a couple of studies from introductory physics in the 1990s, it could have been tempting to dismiss active learning as a cute idea that worked for them but doesn’t work for <insert your class here>. But now it’s hundreds of studies across many fields.

And There’s More Science To Do

So why and when does active learning work? Aye, there’s the rub. The first generation of active-learning research established that it works. The next generation needs to figure out why and when — as Freeman et al. 2014 notes.

The root cause could be explained by cognitive science, as suggested by Redish (’94). Weiman (’07) offers two theories:

• Memory: The root problem with traditional lecture is the working capacity of human short-term memory: at any given time we have a limit of about 7 items in storage, and 4 in processing. Traditional lectures go too fast for that capacity. Our buffers overflow; ideas get dropped on the floor.
• Metacognition: Experts don’t only know facts. They have a mental model that enables retrieval and application, and they introspect to decide whether they really understand. The most effective way to develop those metacognitive skills is through peer collaboration. Consider this question posed by Redish: how do PhD students in your lab become independent scientists? Is it through attending lecture? Or working with peers in the lab to “do science”? Likewise, active-learning lectures build in the time for peer collaboration.

But the devil is in the details. The recent meta-analyses discover some:

• “High intensity” active learning (>66% of class time) is needed to narrow achievement gaps for underrepresented groups. “Low intensity” (<33%) doesn’t cut it. (Theobald et al. 2020)
• The effects are greatest in small (<50 students) classes. (Freeman et al. 2014)
• Active learning has greatest impact on “higher-level cognitive skills” and particularly correction of misconceptions — less so on content knowledge or quantitative skills. (Freeman et al. 2014)

And for this skeptic, those are troubling findings. They suggest that the low-intensity active learning I do in my 400+ student classes won’t have the desired benefit. Is it worth my while anyway? Are there implementation techniques that would make a difference? “More research is needed,” as they say.

Most troubling to this skeptic is this simple fact: these studies aren’t of random faculty. Is sample bias skewing the results? Are the characteristics of the faculty who have adopted active learning in reality the root cause? If the answer is yes — and that active learning turns already good faculty into great — then maybe it’s still worthwhile! But I wouldn’t want to tell all faculty they need to spend effort implementing active learning if active learning in itself is not the cause.

Btw, What Is “Active Learning”?

A common misconception is that active learning requires the full flipped-class model: students read texts and watch videos before class, then exclusively do exercises with peers during class. Implementing that in a way that does not increase student workload — or force them to work every night instead of having agency in their study schedule — is indeed problematic.

But active learning (which historically has gone by other names) can be much simpler. Here are three definitions:

• Interactive engagement: head- and hands-on activities that yield immediate feedback through discussion with peers and instructors. (Hake 1998)
• Deliberate practice: problem solving during class with frequent feedback (Deslauriers 2011)
• Active learning: activities and discussion in class, as opposed to passive listening; emphasis on higher-order thinking; group work. (Freeman et al. 2014)