4 Ways to Ensure Your Lessons Stick with Students
by Charan Ranganath
September 18, 2024
Imagine you’re a student sitting in a classroom discussion. You’re somewhat interested in the topic, and the instructor seems to be doing a good job. The class ends, and 30 minutes later, you try to recall what was discussed. You can remember that your pen was running out of ink, the room was too cold, and the instructor was wearing a pink tie . . . but you can’t remember the key points of the discussion.
As a neuroscientist, I can relate. In my job, I sit through hours of academic talks and read numerous research papers, but I can usually only recall a tiny fraction of that information. I also find myself on the other side—delivering lectures to students, preparing presentations, writing reports, and, most recently, putting together a book—fully aware that most of the details I try to communicate will be forgotten.
Over a century of research on human memory shows that we forget much of what we experience within a day. The small proportion of things we do retain weigh heavily on our future actions. As Nobel Prize–winning psychologist Dr. Daniel Kahneman put it, “We make our decisions in terms of our memories.”
Therefore, for a message to be effective, it must be remembered.
What makes a lesson memorable?
While writing my book, Why We Remember, I faced the challenge of encapsulating over a century of research on the science of memory in a way that readers could understand and apply to their daily lives. Drawing upon that science, I came up with what I call the four Cs of memorable messaging. You, too, can use the concepts from memory science to craft engaging lessons—whether it’s a class activity, an assignment, or a discussion—that will be likely to stick with students.
1- Chunk it up
The human brain can only keep a limited amount of information in mind at any given time. That limit, or what psychologists call “working memory capacity,” might be as small as three to four pieces of information. This bottleneck significantly constrains the amount of information you can expect your students to take in. Fortunately, there is a key loophole: There is no fixed definition for what constitutes one piece of information.
To get around working memory capacity limits, we can use, “chunking,” in which we explicitly tie together the points that we want to convey under the umbrella of a central idea. With this approach, your students can stitch the pieces together in a meaningful way and build a rich memory for that material.
“The human brain can only keep a limited amount of information in mind at any given time.”
For instance, when people would ask me to explain how we can keep our memory functioning well as we get older, I used to give them a long list of things to do. Now, I just give them a simple answer: “Your brain is a body part, so what is good for your body is good for your brain and your memory.” I follow up this simple concept with the specifics, including what to do (aerobic exercise, Mediterranean diet, getting enough sleep, etc.) and what to avoid (chronic stress, infections, air pollution, etc.). By starting with one basic principle, and breaking it down into two subcategories, I organize a disconnected laundry list of facts into a cohesive network of knowledge.
2- Make it concrete
When teaching a complex topic, you can make it memorable by using a concrete example. Research shows that people find it harder to memorize an abstract concept, like “justice,” than something that we can easily visualize or imagine, like “gavel.”
Although I know this as a scientist, it took me a while to incorporate that advice in my own teaching. For many years, I taught classes in which I focused all my time on the concepts that I wanted students to learn. When writing Why We Remember, however, I had to adopt a different approach to make the same material more accessible. So, I started off each chapter with an emotionally engaging story, embellished with sensory details to immerse the reader.
One story involved a birthday party that I organized, which went terribly awry. The story ended with me breaking a piñata with a golf club and “one kid launch[ing] herself like an Olympic gymnast across the yard to get to a Snickers Mini she’d spotted on the grass.” These details didn’t have much to do with my main point, which was to illustrate why some memories stick around and others don’t. But the concrete details in my story exist to elicit an emotional response and provide imagery that will give readers a vivid memory—one they can use as a mental bookmark to pull up the associated information from the chapter.
3- Provide callbacks
Recalling something that we previously learned can make it stronger and easier to access when we will need it. This is why tests can be the most powerful educational tool in an instructor’s arsenal. In one study, researchers showed that when people were trying to memorize words in Swahili, studying the words to retain them was not as effective as trying to recall them on a test. In fact, you can test students before you have even taught them the answer—pre-testing students on what they are about to learn can be just as effective as testing them on what they have already learned.
“When teaching a complex topic, you can make it memorable by using a concrete example.”
Of course, in an educational setting, testing your students is a valuable tool. However, in certain contexts—such as project-based learning or classroom discussions—formal testing isn’t always possible or necessary. In my lab, we explored how this callback technique could be applied in more natural, everyday scenarios. We scanned people’s brains while they were listening to stories, and at one point in each story there was a sentence that referred back to an event that was described a few minutes earlier. During the callback, we saw greater activation of the brain circuitry involved in forming new memories, and the callback helped our subjects retain more information from the story.
Throughout my book, I include a few strategically chosen callbacks such as, “As we found out in the last chapter . . . ” Each callback highlights a connection between the current topic and one I cover earlier in the book, encouraging readers to test themselves by recalling what they read earlier. As a bonus, it helps people chunk the new information with what they’ve previously read, which—as I mentioned earlier—also helps readers remember.
4- Spark their curiosity
If you only focus your lesson on leading up to a final message, you are missing a huge opportunity. After writing over 200 academic papers and thousands of pages of research grants, I have learned that the key to memorable communication lies not in conveying the answer, but in establishing a compelling question.
This intuition is bolstered by brain imaging research conducted in my dynamic memory lab. Using functional magnetic resonance imaging, we found that when people are confronted with a question and are curious to learn the answer, there is a spike in activity in areas of the brain that process dopamine. These brain areas seem to play a role in energizing us to chase rewards (like traveling a long distance to your favorite pizzeria). Moreover, dopamine enhances the brain’s ability to form new memories, which might explain why curiosity turbocharges learning.
“The key to memorable communication lies not in conveying the answer, but in establishing a compelling question.”
Research suggests the key to stimulating that dopamine bump is to highlight a knowledge gap. We all have gaps in our knowledge about the world, but we are often unaware of those gaps. By highlighting the gap between what your students know and what you want them to know, you can elicit a little error signal in their brains, leading to a state that is conducive to new learning.
For instance, the title of my book refers to a simple question: “What is the purpose of memory?” Intuitively, most of us would think that the purpose of memory is to document all our past experiences. Instead, I tell people that memory is not about the past; it is about the future. When confronted with a counterintuitive answer to a seemingly obvious question, students might be intrigued or they might be skeptical, but they are likely to be curious about where the lesson will be heading.
Creating a lasting memory
Over the course of reading this article, I am hoping you might have noticed that I incorporated each of the “Cs” described above to make this article more memorable. I don’t expect you to remember it all, but if you remember one thing from this article, it should be that our immediate experiences are ephemeral. So, if you want to share information that will have a lasting impact, the key is to create a lasting memory.
This article was originally published on hbr.org and has been adapted with the author’s permission.
