The Simple Method That Boosts Memory by 50%

Sometimes the most powerful methods for learning better are also the simplest.



In my latest video essay, I discuss the power of retrieval practice, and explain why students consistently underrate its effectiveness:

Are Mind Maps a Waste of Time?

Mind maps are a popular tool for studying. But, as they’re typically practiced, they underperform retrieval practice by a wide margin.

One objection to this was that the experiment I featured in the video focused on memory, but mind maps are supposed to be a tool for understanding.

But if understanding is good for anything it’s being able to reason flexibly about material and use it to answer novel types of questions. It turns out, the experiment showed that retrieval beat mind maps on inference questions, not just those which could be answered directly from the text.

Memory may be insufficient for understanding, but it is always necessary. You can’t understand something you can’t recall, and so the methods that boost memory are often the same as those that boost understanding.

Another objection may be that, by focusing on concept maps made with the book open, the researchers ignored a more beneficial third alternative: that you could combine concept maps with retrieval practice and do better than both!

Researchers tested that, too. In this paper, the same researchers tried that combination. They found that adding retrieval practice to mind mapping yields the same boost to memory as free recall alone.

In other words, retrieval practice plus mind mapping beats mind mapping with an open book, but the active ingredient driving the efficacy is retrieval—not the mind map.

Even so, I wouldn’t say that mind maps are completely useless. I think they can help organize thinking about a large topic. And, if you’re trying to organize your thinking, you’re probably retrieving, so they may be an easy way to do that kind of practice.

 I think the real takeaway from all this research isn’t that mind maps are pointless, but that retrieval practice is robustly useful and powerful.

Is Harder Learning More Efficient?

Retrieval practice is effortful, and it leads to better learning than less effortful approaches. It’s tempting to conclude from this that more-effortful forms of studying are more effective. Many comments I got on the above video suggested this as an obvious truism.

But, it turns out, this isn’t true either.

The kind of effort used in retrieving knowledge can strengthen memory more than more passive review. But this doesn’t imply that all books, lectures or other forms of “passive” instruction are automatically inferior to “active” mental engagement.

Indeed, there’s a robust literature now showing that studying worked examples actually beats problem solving in the early phase of learning a new skill. Similarly, when difficulty exceeds a certain threshold many study effects, like the efficacy of retrieval practice, disappear or even reverse. This suggests the key to successful learning is about optimizing effort, not maximizing it.

A better maxim might be that effective learning is effortful, but not all effort is effective.

Retrieve, Don’t Re-Read

Despite these caveats, I think retrieval practice remains one of the most powerful learning strategies to have in your toolkit. Memory strengthens through use. You’ll recall more if you strive to remember, not just review.