When students themselves are asked about what they do when studying, they commonly report underlining, high- lighting, or otherwise marking material as they try to learn it (e.g., Cioffi, 1986; Gurung, Weidert, & Jeske, 2010). (18)
On the basis of the available evidence, we rate highlighting and underlining as having low utility. (21)
it may actually hurt performance on higher- level tasks that require inference making. (21)
Dunlosky, et al “Improving Students’ Learning with Effective Learning Techniques” Psychological Science in the Public Interest 14.1 (2013): 4-58.