Highlighting, however, is not enough to get the info stuck in your brain. You’ll have to come back and look at it many more times to make sure it sticks. Now it becomes a question of what method you’ll use to get it to stick; elaboration (using notes and other means of processing) or just rehearsal (reviewing the sentence in the text enough times that it finally sticks.) All the research shows that elaboration, while more difficult than rehearsal, is much more efficient at getting info into your memory. So the trade off is between spending, say, two minutes adding that piece of info into your notes and processing it with questions and diagrams, and then maybe spending an additional ten minutes (spread over days and weeks usually) reviewing it OR spending ten seconds highlighting it and then spending an additional twenty minutes (spread over days and weeks) to make it stick. Bottomline; just highlighting costs you time in the long run if you’re end goal is mastery of the information.