Research shows that typical highlighting may hinder learning. Here are three highlighting strategies that actually work.

Students tend to rely too heavily on highlighting, often at the cost of more effective studying strategies. But don’t throw out those fluorescent markers just yet: When paired with additional strategies that deepen students’ involvement with material—encouraging them to consider it in new contexts while synthesizing different ideas—highlighting can be a powerful learning tool.

"There’s not a lot of thinking involved with the use of highlighters and therefore, there’s not a lot of learning," writes AP psychology teacher Blake Harvard in his blog The Effortful Educator. Students often make the mistake of thinking that because they’ve highlighted something, they’ve absorbed it and are ready to move on. But that’s a mistake, Harvard argues, and it prevents them from truly engaging with the material at a deeper level so that the learning sticks and they’re actively filling in knowledge gaps.

Harvard’s criticism of highlighting is well-founded. In a 2013 study, researchers concluded that despite being a widely-used strategy, "most studies have shown no benefit to highlighting (as it is typically used) over and above the benefit of simply reading." In fact, when students relied only on highlighting as a study strategy, it came with a significant opportunity cost, preventing them from "engaging in other, more productive strategies."

That’s because students often use a highlighter to identify key ideas, names and dates, or material they think might be important for a test, but don’t do the work to process the material more deeply. "Highlighting is the beginning of the learning process, not the end," says Harvard.

The Problem With Highlighting

In the classroom, students frequently highlight text "because it feels like they should," Harvard writes. "Key term? Highlight it. Important person? Highlight it. The teacher said this is important to know? Highlight it." This approach doesn’t push students to carefully consider why they’re highlighting, and perhaps more importantly, might give them a false sense of mastery.

Novice learners typically don’t have the expertise to know what to highlight in the first place, says Katherine Rawson, a professor of psychology at Kent State University. It’s a sort of catch-22 that’s compounded by their misperceptions about highlighting as a productive learning strategy. "Students love highlighting, and at some level, we all understand that," Rawson says. "The problem is that highlighting alone doesn’t really enhance learning all that much." While it may potentially be more productive if students plan to re-study what they’ve highlighted, even that’s risky because "students aren’t very good at identifying what the important information is when they’re highlighting," Rawson says.

That’s because students often lack the metacognitive skills to learn effectively, other researchers have pointed out. Left to their own devices, students are often "poor judges" of their own learning, favoring strategies that require low cognitive effort—such as highlighting text and passively listening to lectures, according to a 2019 study. While such strategies may feel productive to students, they’re superficial and result in information being quickly forgotten.

Experts have also pointed out that students often have a perfunctory approach to highlighting, observing in a 2015 study that it "primarily amounts to a mechanism for tracking progress and does not involve deeper processing."

But highlighters aren’t going away anytime soon. "In my classroom, I see highlighters as a force for good (learning)…when they’re used correctly," Harvard writes. Paired with the right strategies—one recommended by Harvard and two from other educators—highlighting can be a highly productive way for students to interact with a text.

Highlighter Strategy #1: Brain-Book-Buddy

In Harvard’s classroom, highlighting is flipped on its head: the markers are used as tools to help students identify gaps in knowledge. After noticing that his students often take a test, look at their grade, and move on, Harvard developed the brain-book-buddy sequence, a three-step test preparation strategy that exposes blind spots in comprehension.

When taking a practice test, his students write their answers on a sheet of paper with three columns. In the first column, students answer questions using only what they know without checking any external resources. As they write down answers, they highlight in green anything that they feel unsure of. This is a crucial step, says Harvard, because it gets students "thinking about not only what they currently know, but where it comes from in the classroom."

In the second column, students check their notes and textbooks to validate their answers, highlighting additional and corrective information in yellow. Finally, students pair up and record their final answers in the third column, using orange markers to visually highlight the material that improved their responses.

Comparing their answers in each of the three columns lets students see how their understanding changed throughout the activity, Harvard explains. In the first column, his students can see the score they likely would have gotten on a graded test. In columns two and three, they see how much they have left to learn.

Highlighter Strategy #2: Creative Annotations

"When students are asked to underline important parts of texts, they will usually pick the first line that seems appealing or attempt to highlight the whole page of text with pretty-colored highlighters," writes Lauren Gehr, a high school English teacher. It’s a passive, ineffective approach, she says.

If students aren’t interacting with the text, they’re not going to achieve the deeper understanding they need to think critically about what they’re learning. Simply memorizing information isn’t going to make it stick—students’ brains are wired to forget material that isn’t elaborated, applied, or used in some other fashion. So highlighting passages is just a starting point, she tells her students. The next step is to annotate the text, synthesizing information and writing short summaries, reflecting, or even drawing representations of the marked text. This turns what would otherwise be "meaningless highlights" into a "meaningful learning experience," she says.

Gehr also brings collaborative annotations into the mix. "Students annotate the same text and analyze each person’s annotations to find inspiration, discover similarities, or ask questions," she explains. Using online tools like Google documents, students can analyze the same text and share those annotations with their peers.

Highlighter Strategy #3: Student-Generated Questions

Passive study strategies such as highlighting are so "superficial," they may impair long-term retention, says Mirjam Ebersbach, a psychology professor at the University of Kassel. "This superficial learning is promoted by the illusion of knowledge, which means that learners often have the impression after the reading of a text, for instance, that they got the message."

Ebersbach’s research shows that students frequently overestimate how prepared they are for tests, convinced that low-effort studying methods like taking rote notes, highlighting text, and restudying will help them pass their exams. But these strategies fall short, and shouldn’t be exclusively relied upon. Her strategy of choice: student-generated questions.

After highlighting a key idea, students should then generate their own questions—a strategy that should enhance their understanding of the topic, boost interest, and draw in reluctant learners. Start with factual questions, Ebersbach suggests, like recalling key dates, figures, or events. As students become familiar with the strategy, you can encourage them to write more complex questions, or even use their questions for a game of Jeopardy! or a class-wide quiz using Kahoot or Quizlet.

By turning highlights into questions and then quizzing themselves afterwards—or even sharing their questions with the class—students aren’t just passively highlighting text, but actively engaging with the material in a way that involves higher levels of cognitive effort, leading to a deeper, more durable understanding of the material.