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Reading & Comprehension

Annotating While Reading: Write Back to the Text

Limited evidence 5 min read Level: Beginner Reviewed October 30, 2026

Annotating means marking and commenting on a text as you read. Learn which marks help, which do not, and how to try it safely without overdoing it.

Evidence rating: Limited evidence. Highlighting and underlining were rated low utility in a large review of study techniques (Dunlosky et al., 2013), and early studies found little memory benefit from them (Fowler & Barker, 1974). Writing your own comments is different from highlighting, and it may help when it makes you explain the text to yourself (Chi et al., 1994). Still, there are few direct tests of margin annotation, so the benefit is uncertain. How we rate evidence

What it is

Annotating is writing on your reading while you read. You might underline a key sentence, circle a new word, write a question in the margin or add a note such as This contradicts page 12. The goal is to make reading an active conversation with the text.

It helps to separate two habits. The first is highlighting: coloring sentences that look important. Research on this is not encouraging. A large review rated highlighting and underlining as low utility, partly because students tend to mark too much and the act can feel like studying without being so (Dunlosky et al., 2013).

The second habit is writing your own words next to the text. A comment like This is the cause, not the effect forces you to process the idea. A related line of research on self-explanation, which means explaining to yourself what a sentence means and why, found that students who did this often understood texts better (Chi et al., 1994). Annotation can be a way to do self-explanation, but nobody has shown that every kind of annotation works.

Because the evidence is limited, treat annotation as an experiment. Try it for a few readings, then check whether you can recall more afterward than when you only read.

When to use it

  • You are reading something you own, such as a printed textbook, a photocopy or a PDF you can mark.
  • You find your mind wandering while reading and want something to do with your hands.
  • You are reading for an essay or discussion and need to find passages later.
  • You want to track questions and confusion points for class or office hours.

How to apply it

  1. Before you start, choose a small set of marks. For example: one underline for the main claim, a star for something you must remember, a question mark for confusion.
  2. Read one paragraph or short section without marking anything.
  3. Go back and mark only the one or two sentences that carry the main idea. Do not mark more than that.
  4. In the margin, write a short note in your own words: what the passage means, why it matters or how it links to something else.
  5. Write at least one question per page, such as Why did the author choose this example?
  6. When you finish, scan your marks and write a three-line summary at the end of the chapter.
  7. Later, cover the text and use your margin notes as prompts to recall the content.

Step-by-step examples

Example: annotating a history primary source

  1. You read a two-page speech from 1863. After the first paragraph, you underline the sentence that states the speaker's main goal.
  2. In the margin, you write in your own words: He wants soldiers to keep fighting.
  3. You circle a word you do not know and write its meaning after looking it up.
  4. Near the end, you write a question: Who is the audience, and does that change the tone?
  5. At the end, you write one sentence describing the speech, then check it against your teacher's notes.

Example: annotating a biology textbook page

  1. The page explains photosynthesis. You read the first section and then mark only the sentence that defines it.
  2. Next to a diagram, you write a short note: Light reactions make energy; Calvin cycle uses it to make sugar.
  3. You put a question mark beside a paragraph about electron carriers and write Ask in class.
  4. After finishing, you fold the page so only the margin notes are visible and try to explain the process from them.

Advantages

  • Gives you something active to do, which can keep attention on the page.
  • Margin notes help you find key passages later without rereading everything.
  • Writing questions makes confusion visible, so you can ask for help early.
  • Costs nothing and works with any text you are allowed to mark.

Limitations

  • Highlighting alone has little research support and can create a false feeling of learning.
  • Annotation helps only if you think while marking. Mechanical marking does not.
  • It does not replace recall practice. Marking is not the same as remembering.
  • It is not allowed on library books or rented texts, and it can be hard on digital screens.

Common mistakes

  • Highlighting whole pages until nothing stands out.
  • Marking while reading for the first time, before you know what matters.
  • Using only colors and no words, so you never process the meaning.
  • Never going back to the notes after the reading is done.
  • Counting a marked-up page as studied without testing yourself.

Recommended next steps

Part of the path Read More Effectively (step 3 of 5). Next in this path: Summarizing After Reading: Say It Short in Your Words.

References

  1. Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4-58.
  2. Fowler, R. L., & Barker, A. S. (1974). Effectiveness of highlighting for retention of text material. Journal of Applied Psychology, 59(3), 358-364.
  3. Chi, M. T. H., de Leeuw, N., Chiu, M.-H., & LaVancher, C. (1994). Eliciting self-explanations improves understanding. Cognitive Science, 18(3), 439-477.

This guide is general educational information. Study methods work differently for different people, and no method guarantees better grades or results.

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