Highlighting on its own does little to help you learn from a text. A 2013 review rated it a low-utility technique, and a 2022 meta-analysis found that it improves recall somewhat but not comprehension. Marks are useful for something else: leaving you a map back to what mattered.
What the studies say about highlighting
The 2013 review by Dunlosky and colleagues, published in Psychological Science in the Public Interest, evaluated ten study techniques. Highlighting and underlining were rated low utility, along with rereading; the top-rated techniques were practice testing and spreading study over time.
A 2022 meta-analysis by Ponce, Mayer and Méndez in Educational Psychology Review pooled 36 articles published between 1938 and 2019, with 85 effect sizes. When readers highlighted on their own, recall improved (average effect size 0.36) but comprehension did not (0.20). It helped college students (0.39) but not school students (0.24). When the text came with the important material already highlighted by an instructor, both recall and comprehension improved (0.44 each).
Both studies measure learning from academic texts with later tests. They say nothing about the pleasure of reading or about what you do with your personal reading.
What about taking notes by hand instead of on a laptop?
A widely cited study by Mueller and Oppenheimer (2014) reported that longhand note-takers answered conceptual questions better than laptop users. A 2019 replication by Morehead, Dunlosky and Rawson found no consistent differences between groups, not even against a group that took no notes, and concluded that it is premature to say which method is better. Another 2021 replication by Urry and colleagues also did not find that writing by hand improved immediate learning.
For now, the evidence is not strong enough to claim that paper or screen helps you remember more when you take notes.
What marks are for, even if they are not a shortcut
Highlighting not being a powerful study technique does not make marks useless. A line in the margin shows where the sentence you wanted to quote was; a question mark reminds you what you wanted to check; two words of your own record what you thought at the time. These are practical uses, not promises about your memory.
A marking code for your reading
This is an original worksheet proposed by KeepAnalog. Use it on paper or on screen:
- One line in the margin, not whole paragraphs painted over. Mark where the idea is, not the entire text.
- "?" for what you did not understand or want to check.
- "!" for what surprised you or contradicts something you thought.
- "→" plus one word to connect with another reading.
- When you finish, one or two sentences in your own words about the main idea, on the first or last page.
If you ever come back to the text, the code leaves you a map: what mattered, what was left in doubt and what you connected it to.
Where a printed issue fits
KeepAnalog turns public links chosen by one person into a printed issue for Argentina; each link must resolve to an HTML page or a PDF to be included. On paper you can use this code with a pen, but that does not make it a better study technique than a screen. To think about when each format makes sense, see paper or screen by reading task; and to come back to ideas without piling them up, how to learn something new every day.
For now, KeepAnalog's pilot is in Argentina only, with no delivery in the United States.