Ace
Short answer: do not read a PDF from page one to the end and hope it sticks. Skim the headings first, read one section at a time, then close the file and write or say what you remember before checking. Turn each section into questions and answer them again over the following days. On screens, slow down and avoid highlighting everything, because people tend to read digital text faster and more shallowly than paper.
Why reading a PDF feels productive but is not
Reading through material makes it feel familiar, and familiarity is easy to mistake for knowing. A large review of study techniques by Dunlosky and colleagues (2013) rated rereading and highlighting as low-utility: they are the most common habits, but they do little for long-term memory compared with practice testing and spacing out your reviews. Roediger and Karpicke (2006) showed the gap directly: students who practised recalling a text remembered far more a week later than students who reread it.
So the aim with a PDF is to spend less time with it open and more time with it closed, pulling ideas back out.
Five steps to study a PDF properly
- Map it first (five minutes). Read the contents, headings, summary boxes and any learning objectives. Check your course outline for which sections are actually examinable. Skip what is not.
- Read one section at a time. A section is a heading's worth, a few pages at most. Read it properly once, slowly, without highlighting.
- Close the file and recall. Write down or say everything you remember: the main idea, the key terms, any process or formula. This is the blurting method.
- Check and fill gaps. Reopen the section, compare and add what you missed in a different colour. The gaps are what you need to work on.
- Turn it into questions. For each section, write three to five questions you could be asked, with the page number of the answer. Answer them again tomorrow, then in a few days, then the next week (Cepeda et al., 2006).
Studying on a screen vs on paper
A meta-analysis by Delgado, Vargas, Ackerman and Salmerón (2018) compared reading comprehension on paper and on screens across studies published between 2000 and 2017 and found a small but consistent advantage for paper, mainly for informational texts like textbooks. One explanation researchers offer is that people tend to skim on screens.
You do not need to print everything. You do need to counter the skim:
- Turn off notifications and close other tabs while you read.
- Read in full-screen or a reading mode, one page at a time, rather than scrolling fast.
- Do the recall step on paper or in a blank document, away from the PDF.
- Print the few pages that are dense with diagrams or derivations, if that helps you slow down.
What to do with a really long PDF
A 300-page PDF before an exam is mostly a triage problem.
- Prioritise by the syllabus, not by page order. Do the chapters that carry the most marks first.
- Use past papers to see which topics come up. See how to use past papers properly.
- Spread chapters across days so each one gets at least two returns before the exam.
- Skip re-reading on the return visits. Go straight to your questions; reopen the PDF only for what you got wrong.
Writing questions for every section is the slowest part. Ace does that step for you: upload the PDF, choose the chapters, and it writes practice questions from that file only, showing the sentence each answer comes from so you can jump back to the right place. Our PDF to flashcards page explains how it works.
Frequently asked questions
Should I highlight my PDF?
Sparingly, if at all. Highlighting feels useful but research rates it low for long-term learning. Recall and self-testing work much better.
Is it better to print lecture notes?
Paper has a small comprehension advantage for informational text, mostly because people read screens faster. If you read carefully on screen and test yourself away from it, either works.
How long should I spend on each page?
There is no fixed rate. Aim for more time recalling and answering questions than reading; a rough split is one part reading to two parts practice.
Can AI summarise my PDF for me?
It can, but reading a summary is still reading. Use AI to make questions from the PDF instead, and answer them from memory.
Sources
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4–58. APS summary
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255. PubMed
- Delgado, P., Vargas, C., Ackerman, R., & Salmerón, L. (2018). Don't throw away your printed books: A meta-analysis on the effects of reading media on reading comprehension. Educational Research Review, 25, 23–38. doi.org/10.1016/j.edurev.2018.09.003
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380. PubMed
