How to revise from lecture slides (without just rereading them)

By oosync editorial team · Updated 2026-10-15 · 3 min read

Most students revise from slides by scrolling through them, nodding along and moving on. It feels efficient because the slides look familiar. But familiarity is not memory: recognising a slide is much easier than recalling what it says when it is not in front of you, which is what the exam asks. This guide gives you a method that turns slides into real revision.

Why rereading slides does not work

Research on study techniques consistently finds that rereading and highlighting are among the least effective ways to prepare for an exam, while practice testing and spacing out your study are among the most effective (Dunlosky and colleagues, 2013). Rereading slides gives you the feeling of knowing. Testing yourself shows you what you actually know, and the act of recalling makes the memory stronger.

So the rule for revising from slides is simple: look at the slide, then look away and explain it.

The method: five passes per lecture

1. Skim the whole deck first

Spend five minutes going through every slide quickly. Note the structure: what are the three to five big ideas of this lecture? Write them down as headings on a blank page. This gives every detail a place to go.

2. Cover and explain

Go through the slides one at a time. For each one:

1. Read the slide.
2. Cover it, or look away.
3. Explain it out loud or in writing, in your own words, as if to a classmate who missed the lecture.
4. Check. What did you miss?

Anything you cannot explain is a gap. Mark it, and fill it from the recording, your notes or the reading, not by staring at the slide.

3. Write questions, not summaries

For every important slide, write one question you could be asked in the exam. Put the question on one side and the answer, with the slide number, on the other. Good questions ask why, how, what would happen if, or how two ideas compare. These questions become your flashcards and your practice exam later.

4. Make a one-page summary from memory

Close the slides. On one page, write everything you remember about the lecture under the headings from step 1. Draw the key diagram from memory. Then open the slides and add what you missed in a different colour. The different colour shows you exactly where to focus next time.

5. Come back later

Revisit the questions after a day or two, then after a week, then after a few weeks. Each time, answer from memory first. Spacing reviews out like this helps you remember for much longer than doing the same amount of work in one sitting.

A weekly routine that keeps up with lectures

Keeping up during term makes exam season much lighter. If you are already behind, start with the lectures that past papers ask about most.

Common mistakes

• Copying slides into notes. If your notes look like the slides, you have moved text, not learned it.
• Highlighting everything. If everything is yellow, nothing stands out.
• Revising one module for a whole week. Mixing two or three modules per day spreads your practice and keeps every module moving.
• Skipping the diagrams. Exams love diagrams. Practise drawing them from memory.

How oosync helps

oosync is built for this routine. Add your slides (PowerPoint or PDF) to a module and it lays out a note page by the slides' own headings, so you can write each section in your own words. You can listen to the material read aloud as a first pass, generate flashcards from a slide deck and review them on a spaced-repetition schedule, and make a practice exam from the same slides when you are ready to test yourself. The free plan covers 2 modules with up to 3 of your own materials each.

It does not replace the thinking. The cover-and-explain step is yours, and it is what makes revision stick. For turning slides into notes in the first place, read how to turn lecture slides into study notes.