The three problems
It's passive. Dragging a pen across a sentence requires you to recognise that the sentence looks important. It does not require you to understand it, and it certainly does not require you to be able to produce it later. Recognition is not recall, and the exam asks for recall.
It's decided too early. You highlight on your first read, when you understand the material least. Which is why so many textbooks end up with the first half of every chapter fully yellow and the second half untouched — the highlighting records your stamina, not the importance of the content.
It creates false fluency. Later, you flick through the highlighted pages, recognise every yellow sentence, and feel prepared. That feeling is the fluency illusion in its purest form, and it is the single most expensive mistake in studying.
The fix takes two minutes
- Highlight on the second pass, not the first. By then you actually know what matters.
- Cap yourself. Three highlights per page, maximum. Scarcity forces judgment; a page that is 40% yellow has told you nothing.
- Then do something with it. For each highlight, write a question it answers in the margin. You have now converted a passive artefact into a retrieval prompt — which is the whole difference.
- Better still, don't highlight — blurt. Close the book and write what you remember. See the blurting method.