Ace
Short answer: stop the video regularly and test yourself on what you just heard. In a Harvard study, students who answered short quizzes between sections of an online lecture mind-wandered about half as often and remembered more of it than students who just watched or re-studied. Watch in short chunks, recall each chunk from memory, then practise with questions built from the lecture itself, not a summary of it.
Why doesn't watching YouTube lectures stick?
Because watching is passive. A clear explanation feels like understanding while it's playing, but recognising an idea when someone explains it is not the same as being able to produce it in an exam. Videos make this worse in two ways: they never stop to check on you, and it's easy to drift off while the video keeps going.
Szpunar, Khan and Schacter (2013) measured exactly this. Students watched a 21-minute recorded statistics lecture. When checked during the lecture, those who simply watched reported their mind wandering about 40% of the time. Students who answered short tests between segments wandered about half as often, took more notes and remembered more on the final test. A later study with a longer video lecture found the same benefit for overall learning (Jing, Szpunar and Schacter, 2016).
How should you study from a YouTube lecture?
1. Watch in short chunks
Pause every 8 to 10 minutes, or at each new heading in the lecture. Long, unbroken watching is where attention goes.
2. Recall before you rewind
At each pause, close the video and write or say the main points from memory. Then rewind to check what you missed. This is active recall, and it's the step that turns watching into learning.
3. Turn the lecture into questions
After the video, practise with questions on what it actually said. Write them yourself, or let a tool build them from the lecture. With Ace you can paste a public YouTube lecture link and get practice questions written from the lecture's own words, with the line from the lecture that backs each answer shown under it.
4. Watch at normal speed for new material
Speeding up is fine for review, but for a topic you're learning for the first time, a speed that lets you pause and think usually beats racing to the end. Use the time you save by not re-watching for practice instead.
5. Come back to it in a few days
Don't re-watch the whole video. Answer the questions again after one day, three days and a week. Each successful recall slows down forgetting, as our post on the forgetting curve explains.
Why isn't a ChatGPT summary of the video enough?
Pasting a transcript into ChatGPT and asking for a summary is quick, and summaries are useful for getting the outline. But there are three problems if that's all you do:
- A summary is still reading. Reading a shorter version is still passive, so you get the same "I know this" feeling without the recall that makes it stick.
- It may add things the lecture didn't say. A chatbot can blend in general knowledge or get details wrong, and in an exam your lecturer's version is the one that counts. See can you trust AI study answers?
- You can't easily check it. Without the exact line from the video, you can't tell whether a point came from the lecture or from the AI.
Use ChatGPT for the overview if you like, but do your practice on questions that come from the lecture itself and show you where each answer came from. That's what Ace is built to do; if you prefer ChatGPT, our guide to getting ChatGPT to quiz you shows how to make it test you rather than tell you.
Can you study with friends from a YouTube lecture?
Yes, and it helps you actually finish the video. Agree on a lecture, watch it separately, then quiz each other or play a duel on the same questions. Ace can put a friend on the other side of the same set; see how to study with friends.
Frequently asked questions
Is learning from YouTube as good as a real lecture?
It can be, if you study actively. The format matters less than what you do with it: pausing to recall and testing yourself afterwards works for live and recorded lectures alike.
Should I take notes while watching lecture videos?
Brief notes at each pause help, especially if you write them from memory rather than copying while the video plays. In the Harvard study, students who were tested during the lecture took more notes, not fewer.
Can Ace make questions from any YouTube video?
Ace works with public YouTube lecture links. It uses the video's captions to build questions from what the lecture says.
Is watching lectures at 2x speed bad?
For reviewing something you already know, it's usually fine. For new, difficult material, slow down and pause to recall, because understanding needs time to think.
Sources
- Szpunar, K. K., Khan, N. Y., & Schacter, D. L. (2013). Interpolated memory tests reduce mind wandering and improve learning of online lectures. Proceedings of the National Academy of Sciences, 110(16), 6313–6317.
- Jing, H. G., Szpunar, K. K., & Schacter, D. L. (2016). Interpolated testing influences focused attention and improves integration of information during a video-recorded lecture. Journal of Experimental Psychology: Applied, 22(3), 305–318.
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
