Don’t treat highlighting, rereading, and summarizing as primary study methods

16. Don’t treat highlighting, rereading, and summarizing as primary study methods

Cost: No cost at all; actually saves time. These methods are easy to apply and give you that “I’m studying” feeling.

In plain terms: Highlighting and rereading are the most common study habits among students, yet both rank at the very bottom among ten widely used learning strategies. Summarizing, keyword memorization, and visualizing text with images also fall into the lowest tier. They’re not completely useless, but only work under very specific conditions, so spending the same amount of time on self-testing yields far better results.

Benefit: This review evaluates ten common study methods based on how well their effectiveness holds across different learning contexts, student traits, materials, and assessment formats. The highest-rated strategies are practice testing and spaced practice. Methods rated as moderately effective include elaborative questioning, self-explanation, and interleaved practice. The five least effective methods are summarizing, highlighting (or underlining), keyword memorization, visualizing text with images, and rereading. The review also notes that while most students report using rereading and highlighting, these methods do not reliably improve academic performance; they should be replaced with other approaches such as practice testing instead of rereading.

Evidence grade: A

Sources: Dunlosky J, Rawson KA, Marsh EJ, Nathan MJ, Willingham DT (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. <https://doi.org/10.1177/1529100612453266>

Notes: You can use highlighting to mark sections you plan to self-test later, but the problem arises when highlighting itself is mistaken for actual learning. The review also clarifies that being in the lowest tier does not mean these methods have zero value — they simply work only under narrow circumstances and require further research. For alternative study actions, see item 14 (self-testing after closing the book) and item 15 (spreading study time across multiple days).