Key Takeaways
- Highlighting and underlining are among the least effective study strategies according to cognitive science research.
- These techniques create an illusion of learning without producing meaningful, durable memory.
- Active strategies like retrieval practice and elaborative interrogation significantly outperform passive marking.
- How you study matters far more than how many pages you've marked up.
The Gap Between Feeling Productive and Actually Learning
Pick up any used college textbook and you'll find it — entire pages awash in yellow, pink, and blue. Highlighting feels purposeful. It signals effort. It gives the brain a satisfying sense of progress. The problem is that this sense of progress is largely an illusion.
A widely cited review of study techniques published in Psychological Science in the Public Interest evaluated highlighting and underlining as low utility strategies — meaning the research evidence for their effectiveness is weak relative to the effort they require. Yet surveys consistently show these remain the most commonly used study habits among students at every level.
Understanding why highlighting feels effective — and why that feeling misleads — is the first step toward replacing it with strategies that actually work. See the full ranking of study techniques by evidence for a broader picture of where common methods stand.
Myth
Highlighting important passages helps you remember them better because you're identifying what matters.
Fact
Selecting text to highlight is a low-level cognitive task that rarely produces durable memory on its own.
The act of highlighting requires recognition — deciding something looks important — but not processing. Research on levels of processing suggests that memory is stronger when information is encoded deeply, through meaning-making and connection-building. Dragging a marker across a sentence does not force that deeper engagement. Studies have shown that students who highlight perform no better on comprehension tests than students who simply read the same material without marking it.
Myth
Underlining while reading is a form of active learning.
Fact
Underlining is passive engagement dressed up as active — it lacks the generative effort that builds lasting memory.
Active learning, in a cognitive science context, means the learner is generating something: an answer, a connection, a summary, a question. Underlining requires none of that. It keeps your eyes on the page and your attention on surface features — sentence structure, keyword frequency — rather than on meaning. Research consistently separates generative strategies (retrieval practice, elaboration) from passive strategies (rereading, highlighting), with the former producing substantially better outcomes. Explore why passive habits persist even when students know better.
Myth
Highlighting helps you study more efficiently because you can review only the marked material later.
Fact
Review sessions built around highlighted text still expose learners to information passively, repeating the same low-utility process.
The efficiency argument assumes that rereading highlighted passages is a good form of review — but rereading itself is also a low-utility strategy. When students return to a marked page, they tend to read the highlights the same way they read the original: passively. There is no self-testing, no gap in memory to bridge, no effortful retrieval. The efficiency gain is largely illusory. Truly efficient review involves spacing, interleaving, and self-quizzing — none of which are enabled by a page of colored text.
Myth
Students who highlight more are more engaged and will naturally retain more.
Fact
Heavy highlighting can actually impair comprehension by fragmenting a text into disconnected pieces.
When readers highlight too much — a common pattern, since everything can seem important in the moment — they paradoxically make it harder to identify the genuine core ideas. Research has found that students tend to over-highlight, marking material indiscriminately. This not only fails to support learning but can disrupt the reader's ability to see relationships between ideas. Comprehension depends on understanding how concepts connect, not on cataloging individual sentences. Excessive highlighting breaks that connective tissue.
What to Do Instead: Higher-Utility Alternatives
Abandoning highlighting doesn't mean abandoning your textbook — it means engaging with it differently. The strategies below are grounded in cognitive science and have strong research support for producing durable learning.
Low
Utility rating for highlighting in research
A comprehensive review in Psychological Science in the Public Interest rated highlighting and underlining as low-utility study strategies based on available experimental evidence.
~50%
More information recalled with retrieval practice
Multiple studies have found that retrieval practice — self-testing — can roughly double the amount of material recalled compared to equivalent time spent rereading.
- Retrieval practice: After reading a section, close the book and write down everything you remember. This act of pulling information from memory — rather than re-exposing yourself to it — strengthens the memory trace significantly. Active recall outperforms passive review by a wide margin in controlled studies.
- Elaborative interrogation: Ask yourself why and how as you read. Generating explanations forces deeper processing than recognizing a highlighted sentence ever could.
- Spaced practice: Distribute study sessions across multiple days rather than concentrating them. Spaced repetition produces far better long-term retention than massed cramming sessions.
- Structured note-making: Paraphrase content in your own words, create outlines, or draw concept maps. The act of transforming information requires understanding, not just recognition.
For a practical framework, learn how to structure a study session that actually sticks using these evidence-backed approaches from start to finish.
Don't Just Add Highlighting on Top of Better Strategies
A common response to this research is to keep highlighting as a warm-up and add retrieval practice on top. While adding retrieval practice is always beneficial, be cautious: if highlighting still dominates your study time, the efficiency problem remains. Aim to make generative strategies — self-testing, elaboration, spaced review — the core of your sessions, not an afterthought.