As I prepared to write this column, I relied on some pretty typical study techniques. First, as I’ve done since my student days, I generously highlighted key information in my background reading. Along the way, I took notes, many of them verbatim, which is a snap with digital copying and pasting. (Gotta love that command-C, command-V.) Then I reread my notes and highlights. Sound familiar? Students everywhere embrace these techniques and yet, as it turns out, they are not particularly good ways to absorb new material. At least not if that’s all you do.
Researchers have devoted decades to studying how to study. The research literature is frankly overwhelming. Luckily for all of us, the journal Psychological Science in the Public Interest published a review article a few years ago that remains the most comprehensive guide out there. Its 47 pages hold valuable lessons for learners of any age and any subject — especially now, with end-of-semester exams looming.
The authors examined ten different study techniques, including highlighting, rereading, taking practice tests, writing summaries, explaining the content to yourself or another person and using mnemonic devices. They drew on the results of nearly 400 prior studies. Then, in an act of boldness not often seen in academic research, they actually awarded ratings: high, low or moderate utility.
The study strategies that missed the top rating weren’t necessarily ineffective, explains the lead author John Dunlosky, a psychology professor at Kent State University, but they lacked sufficient evidence of efficacy, or were proven useful only in certain areas of study or with certain types of students. “We were trying to find strategies that have a broad impact across all domains for all students,” Dunlosky says, “so it was a pretty tough rating scale.”
In fact, only two techniques got the top rating: practice testing and “distributed practice,” which means scheduling study activities over a period of time — the opposite of cramming.
Practice testing can take many forms: flashcards, answering questions at the end of a textbook chapter, tackling review quizzes online. Research shows it works well for students from preschool through graduate and professional education. Practice tests are especially effective when they require “free recall” of learned content, as opposed to what researchers call “recognition tasks” such as true-or-false questions or multiple-choice. And that’s regardless of which format the final exam will follow.
Testing yourself works because you have to make the effort to pull information from your memory — something we don’t do when we merely review our notes or reread the textbook.
“We know that the act of retrieval is an extremely potent learning experience,” says cognitive psychologist Thomas Toppino, who chairs the department of Psychological and Brain Sciences at Villanova University. “We have tons of evidence about the relative effectiveness of retrieval as opposed to restudying.”
As for distributed practice vs. cramming, Dunlosky and his fellow authors write that “cramming is better than not studying at all,” but if you are going to devote four or five hours to studying for your biology mid-term, you would you be far better off spacing them out over a several days or weeks. “You get much more bang for your buck if you space,” Dunlosky told me.
The reasons for this are not fully understood, but probably have to do with a process called memory consolidation. As we revisit information over time, the memory becomes more stable and less easily disrupted. Neuroscientists believe this partly reflects the transfer of the memory from the hippocampus in the mid-brain to areas in the cerebral cortex. Revisiting the content at different times on different days also means it may become attached to more cues — an idea called “encoding variability.” So, if you are sitting in the library with the sun pouring through the windows as you study the Krebs Cycle, and then you study it again a few days later with a classmate over snacks in your kitchen, you’ve attached that content to a range of associated memories that may help you retain it.
Combining self-testing with distributed practice is especially powerful. “Never test yourself immediately after you study,” Toppino says. “You’re going to grossly overestimate how well you know the information if you test yourself right away.”
Even better is to get some sleep between your study sessions. Memory consolidation is known to occur during sleep. A 2016 study by Toppino and several colleagues in France has shown that if you interpose sleep between two study sessions, you’ll remember more — and in a much more lasting way — than if you study for the same amount of time without a sleep break. In addition, when you come back and review material after sleeping, you’ll master it more quickly. In Toppino’s study, which involved learning Swahili words, the longer students slept, the faster they mastered the vocabulary words in their post-sleep study session and the better they remembered them one week later.
While much of this information has been known to researchers for years, it doesn’t seem to filter down to students or their teachers. A report released last year by the National Council on Teacher Quality found, shockingly, that 85 percent of the textbooks used to train teachers in how students learn had less than a page on validated strategies; 59 percent of the 48 education psychology textbooks surveyed offered not one sentence.
Students themselves are often misinformed or just plain disorganized. To take advantage of distributed practice and sleep, you’ve got to plan ahead and schedule your studying. As for self-testing, Toppino laments, “there’s a strong tendency for people to think that testing is for evaluation” and yet they miss the point that it is also for assessing their own knowledge gaps and where to focus their efforts.
Other study strategies besides the top two in Dunlosky’s paper can be useful. For example, there’s fairly good evidence to support “self-explanation” and something called “elaborative interrogation,” in which you ask yourself why the facts and concepts you’re learning are true. There’s even a place for highlighting. “The killer is that for many students the strategy they bring to the table to learn the content they’ve highlighted is just rereading it over and over again,” Dunlosky says. “They need to do more engaging things.”
Turns out that he’s a fond of highlighting as I am: “I still have my favorite highlighter,” he told me. “I would never give it up.”