How to Study Lecture Slides (Without Just Rereading Them)
· 5 min read
To study lecture slides, don't read them. Question them. Fill in what the professor said that isn't on the slide, turn each slide title into a question, answer it without looking, and come back to the ones you miss a few days later. Slides are an outline of the lecture; the studying happens when you rebuild the lecture from that outline.
Here is how to do that, step by step.
Why slides are hard to study from
Slides were made to be talked over. A slide that says "Glycolysis: 2 ATP net, cytoplasm, anaerobic" made sense while your professor was explaining it. Three weeks later it is a list of words you recognize but couldn't explain.
That recognition is the trap. Flipping through 80 slides feels like studying because every slide looks familiar. But the exam won't show you the slide. It will ask you to produce what's behind it. Research on study techniques is consistent that rereading builds the feeling of knowing much more than the knowing itself (Dunlosky et al., 2013).
So the goal is to get from "I recognize this slide" to "I can explain this slide with it closed."
Step 1: Before the lecture, skim for five minutes
If the slides are posted before class, flip through them quickly. Don't try to learn anything. Just notice the headings and the words you don't know. When the professor reaches them, you'll be listening for the explanation instead of copying the slide.
Step 2: During the lecture, write what isn't on the slide
Don't copy the slide; you already have it. Write down what is said:
- examples the professor gives
- "this will be on the exam" or "people always get this wrong"
- the why behind a list or a formula
- anything drawn on the board
If you take notes on a laptop or tablet, write directly on the slide PDF. On paper, number your notes with the slide number.
Step 3: Within 24 hours, turn each slide into a question
This is the most important step and it takes about 15 minutes per lecture.
Go through the slides and write one question for each slide (or each idea, if a slide is crowded). The slide title is usually the question in disguise:
| Slide title | Question to write |
|---|---|
| Glycolysis overview | Where does glycolysis happen, and what does it produce? |
| Limits at infinity | How do you find the limit of a rational function as x → ∞? |
| Federalism | How does federalism split power, and where in the Constitution does it say so? |
| Le Chatelier's principle | What happens to an equilibrium when you add more reactant? Why? |
Then close the slides and answer each question out loud or on paper. Check. Mark the ones you couldn't answer. That list is what you study next, not the whole deck.
This is called active recall, and it is the single most useful thing you can do with slides. (We explain it fully in how to do active recall.)
Step 4: Fill the gaps from the textbook
When a slide makes no sense even with your lecture notes, go to the textbook section it came from. Don't read the whole chapter. Read the part that explains that one slide. Add a one- or two-sentence explanation in your own words next to the slide.
How to turn lecture slides into notes
If you want proper notes instead of annotated slides, keep them short. For each slide or group of slides, write:
- The point: in one sentence, what is this slide trying to teach?
- The detail you need: definitions, the formula, the steps, the date.
- One example: from the lecture, the textbook or your own.
- The question: the one you wrote in step 3.
A 60-slide lecture usually becomes two or three pages. If your notes are as long as the slides, you are copying, not summarizing.
How to make flashcards from lecture slides
Slides are full of good flashcard material: terms, definitions, labeled diagrams, lists of steps, formulas. A few rules:
- One fact per card. A whole slide on one card is a reading exercise, not a flashcard.
- Ask, don't label. "Mitochondria" → "powerhouse" is weak. "Which organelle makes most of the cell's ATP?" is better.
- Lists become several cards. "Name the 4 stages of mitosis" plus one card per stage: "What happens in anaphase?"
- Diagrams: cover the labels and name them, or put a cropped diagram on the front.
- Formulas: front = when you'd use it, back = the formula. Then do one problem with it.
You can type them quickly and print or study them in our free flashcard maker, or export them to Anki or Quizlet from there.
Flashcards cover the what. For the how and why (processes, proofs, cause and effect) practice problems and explaining out loud work better than cards.
Step 5: Space it out
Go back to your question list a few days later, then again a week later. Each time, only study the questions you miss. Spreading reviews out like this is one of the most reliable ways to make things stick (Cepeda et al., 2006), and it makes the week before the exam a review instead of a first look.
If you have several classes and an exam date, the free study schedule maker will lay out those reviews day by day.
Can AI help you study lecture slides?
Yes, if you use it to quiz you rather than to summarize for you. A summary of your slides is just a shorter thing to reread. What helps is AI that turns the slides into questions you have to answer.
A few practical notes:
- Most tools read PDF, not PowerPoint. Export first: File → Save As → PDF in PowerPoint or Keynote, File → Download → PDF in Google Slides.
- Scanned slides (images inside a PDF) often can't be read as text; photos of each slide usually work better.
- Check what it writes against the slides. AI can get details wrong, and a confident wrong flashcard is worse than none.
Orbind does this with your PDF: it reads the slides, works out which ideas build on which, and turns them into short lessons that quiz you from the first idea up, plus a practice quiz and flashcards. More on that in PDF to quiz.
Mistakes to avoid
- Highlighting slides. It feels like work; it isn't studying.
- Rewriting slides by hand, word for word. Slow, and it's still copying.
- Studying in slide order only. Once you know the deck, shuffle your questions. The exam won't ask them in order.
- Skipping the lecture because "the slides are posted." The slides are the half of the lecture that's easy to get. The other half is what you were there for.
- Starting the week before. Fifteen minutes within a day of the lecture saves hours later.