Picture this: It’s Monday and Ms. D’Angelo, a seventh-grade science teacher in the South Bronx, gives her students a homework assignment about food chains that is due in one week. The assignment asks students to teach a family member about this concept by completing a model food chain together.
The following Monday, Ms. D’Angelo is surprised to see that that some of her students seem to understand the material at a deep level—they even use new vocabulary terms with great fluidity. These same students appear be much more confident than usual when engaging in the class discussion. Ms. D’Angelo scans her grade book and notices that these students are the same the ones who completed the homework assignment.
Their teacher is in shock. “I couldn’t believe it,” she tells me. “I’ve never seen homework make such a difference.” She then points to Sofia, one of her students who shined particularly bright during the class discussion. Sofia wasn’t a poor student, but Ms. D’Angelo had never heard her speak like such a scientist before.
Was it coincidence, or something more? Perhaps it’s the work of “learning by teaching,” also known as the Protégé Effect. On its face, the concept is simple and intuitive: When you explain something to someone else, you understand it better. But could it really explain what Ms. D’Angelo witnessed in her classroom?
I have recently become very interested in these questions because the Protégé Effect is something we are now trying to leverage at the nonprofit I work for, PowerMyLearning, which strengthens the triangle of student-family-teacher relationships. I had a hunch that this learning strategy might be underutilized and could be something that more teachers would like to try. Acting on my hunch, I spoke with two prominent learning scientists to unpack the science behind why this strategy works.
I first contacted Bror Saxberg, vice president of learning science at the Chan Zuckerberg Initiative. Bror told me he is a big believer in encouraging teachers to apply learning science in their classrooms because “the informal understanding of how learning works often doesn’t line up with the evidence that we’re gathering on how learning actually works.”
Bror encouraged me to talk to Richard E. Mayer, who is a major figure in education psychology and has made significant contributions to theories of cognition and learning.
Richard confirmed my hunch that learning by teaching is a newer and under-studied strategy that more teachers should take advantage of. He said most teachers know about many other evidence-based learning strategies, such as summarizing, mapping and self-testing, but learning by teaching tends to not get as much spotlight. Richard noted that this learning strategy is usually thought of as “peer tutoring” but there are many other ways to go about it.
Perhaps most interestingly, learning by teaching has one of the largest effect sizes of the strategies he has studied. For that research, Richard and his former student Logan Fiorella (currently an assistant professor at the University of Georgia) conducted a random control trial that compared groups of students who used the learning by teaching strategy with those who do not.
They found that when students actually teach the content of a lesson, they develop a deeper and longer-lasting understanding of the material than students who do not teach it. Interestingly, they found that the act of preparing to teach alone can lead to short-term gains, but the act of preparing to teach coupled with actually teaching another person is what leads to long-term retention and deeper learning.
Richard said he was most surprised by the magnitude of the effect size, or difference between the two groups: It was 0.77, which can substantially increase student grades. Education researcher John Hattie says an effect size of 0.5 is equivalent to a one grade leap, and an effect size of 1.0 is equivalent to a two grade leap. Therefore, we can deduce that learning by teaching can potentially improve C students to a B+ or even an A-.
Why is this? Richard said that when students are told they are going to have to teach something, they prepare better. Then when the students actually do the teaching, the questions asked by their “pupil” help them build knowledge by elaborating on the material, monitoring their own understanding and fixing misunderstandings—all of which help students construct deeper meaning and long-term understanding. He said that from a student’s perspective, it’s when you take the material and “mentally re-organize it and integrate it with what you already know—that’s how you make sense out of it.”
It turns out the benefits to learning by teaching are not limited to comprehension; the strategy also helps students develop essential social-emotional learning skills.
Learning by teaching can help improve student efficacy, confidence and communication skills. In addition to learning content, Richard said that students learn productive beliefs about themselves. In his words: “If students feel confident enough to explain it to someone else, they might develop a higher self-efficacy. That’s going to be motivating to see themselves as competent learners.”
So, there are clear benefits of students teaching others, but who should those “others” be? In the case of peer tutoring, it’s typically other students. But imagine if we could use this strategy to engage grandparents, younger siblings or mom and dad, as Ms. D’Angelo did.
Richard hypothesized that teaching family partners could increase the impact he saw in his studies because students are teaching people with whom they have relationships, and who ask meaningful questions. He says, “When you work with your parents, I think that builds a relationship where you feel that your parents are proud of you because you’re showing you know something, and they’re recognizing that you’re capable of doing this. And we know that if you feel that your parents have confidence in you, it gives you confidence.”
Bror also emphasized the benefit of relationships. He said students can learn valuable social skills on how to communicate with their family partners. Generally, if students are communicating with someone they trust in a safe environment (at home), they are going to feel more confident.
At PowerMyLearning, we are exploring the benefits of learning by teachingthrough Family Playlists. Family Playlists are interactive assignments where students “teach” what they learned in class to a parent at home, and then the parent gives feedback to the teacher. In short, Family Playlists “light up” the triangle of learning between students, teachers, and families while leveraging the learning by teaching strategy.
The results we have seen—like in Ms. D’Angelo’s classroom—reflect Bror and Richard’s observations. Ms. D’Angelo’s saw the magic that can happen after students teach their family partners. She could see that her students were more confident in the lesson. As an extra benefit, parents also showed a sense of pride in seeing their child “teach” them. For example, in Sofia’s Family Playlists report, her mother noticed her daughter’s enthusiastic expressions when explaining the material, and how proud it made her.
Given all these positive outcomes, I asked Richard if there is any downside to using the learning by teaching strategy. He cautioned that the approach could backfire if students do not fully understand the concept before teaching it. Students can actually become more invested in the wrong explanation. To avoid this outcome, Richard said teachers should make certain that students understand the concept before they teach it. While this downside is something we are aware of, we still have more to learn.
After talking with Bror and Richard, I am even more excited about the learning by teaching strategy. The learning science is clear and the concept is simple. Learning by teaching is a strategy anyone can do and we know it improves learning outcomes. I would love to see more teachers follow in Ms. D’Angelo’s footsteps and try out this strategy in their classrooms. Who knows what we’ll learn.