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How to study from a recorded lecture without listening twice

By · Notibo

Published · 7 min read · updated

Key takeaways

  • Get a transcript first. Ninety minutes of audio is around 10,000 words you can skim, search and cut; ninety minutes of audio is ninety minutes.
  • Structure the transcript into headings the same day, then write one question per heading. The questions are what you revise from, not the recording.
  • Timestamp the parts you did not follow and replay only those. Imperial and Sheffield both tell students not to rewatch a lecture in full unless they missed it.
  • Same day: transcript, headings, questions, about half an hour. Day three: answer the questions from memory. Day seven: answer them again and repair the gaps.
  • Replaying the whole lecture feels like work and teaches little. Rereading was rated low utility in the 2013 Dunlosky review, and a replay is rereading with a pause button.

Short answer first: get a transcript, cut it into headings, write one question per heading, mark the timestamps you did not follow, and replay only those. Do that the same day in about half an hour, answer the questions from memory on day three and day seven, and you will not need to hear the lecture again.

Recording a lecture is easy. Doing something with the recording is where most students stall, because the obvious next step, listening to it again, takes as long as the lecture did and teaches surprisingly little. This is the workflow that replaces it.

Why not just listen to it again?

Because a replay is rereading with a pause button, and rereading is one of the weakest study methods there is. In the 2013 review by Dunlosky and colleagues, rereading was rated low utility while testing yourself and spacing your study were rated high. A lecture replay has the same problem in a slower format: the material feels familiar on the second pass, the familiarity feels like knowledge, and the exam finds out otherwise.

The universities that provide lecture capture say the same. Imperial College's guide to using lecture recordings tells students to rewatch in full only if they missed the lecture, and adds that the act of deciding which parts to revisit is itself part of the learning. Sheffield's lecture capture guide says the same, and adds that the revisiting should happen within two or three days, not in revision week.

There is a cost argument too. A 90 minute lecture is around 10,000 words of speech. As audio, you can only move through it at the speed it was spoken. As text, you can skim it in ten minutes, search it, and delete the half that was administration, repetition and jokes.

What do you do the same day?

Five steps, about half an hour, done before you go to bed on the day of the lecture. The same day matters because the transcript makes most sense while you still remember the room, and because the first review is the one that stops the forgetting curve from doing its worst.

Step 1: Get the transcript

Run the recording through a transcription tool in the language the lecture was given in. Do not read it yet. If your university's lecture capture produces captions, export those. If you recorded on your phone, upload the file to a tool that handles your language; a Danish lecture through an English only engine produces nothing usable. Transcription versus notes covers what a raw transcript is and is not.

Step 2: Structure it

Skim the transcript once and insert headings wherever the lecturer changed topic. Most 90 minute lectures have five to eight. Delete the housekeeping at the start, the repeated announcements and any tangent that will not be examined. This is the step that turns 10,000 words into two pages, and it is the step an AI notes tool automates; if you use one, this is the output to check rather than to write. The habits in effective note taking apply to a transcript as much as to a notebook.

Step 3: Pull the questions out

Under each heading, write one to three questions the section answers. "What are the three assumptions of the model?" "Why does the reaction need a catalyst?" Write the question, not the answer; the answer is in the section, and you will produce it from memory on day three. The Cornell method does this with a cue column and works just as well on a transcript as on live notes.

Step 4: Timestamp the hard parts

Wherever you did not follow the argument, note the time in the recording next to the heading. These are the only passages you will ever replay. Most lectures produce two or three of them, and each is a few minutes long.

Step 5: Answer once, from memory

Close the transcript and answer your own questions on paper or out loud. Mark the ones you could not. Ten minutes. This is the first retrieval, and it is what makes the difference on day seven: in Roediger and Karpicke's 2006 experiments, students who took a recall test after studying a passage remembered far more a week later than students who reread it, even though rereading looked better on an immediate test.

What do you do the week after?

The same day pass produces two pages of structured notes with questions and a short list of timestamps. The week after is three short sessions.

When What How long
Same day Transcript, headings, questions, timestamps, one answer pass 30 to 40 minutes
Day 3 Answer every question from memory. Replay the timestamped passages you still cannot answer. 10 to 15 minutes
Day 7 Answer every question again, shuffled with the week's other lectures. Rewrite the notes under any heading you still get wrong. 15 minutes
Before the exam The questions only, on the spaced repetition ladder. The recording is not opened. A few minutes per lecture

Day three is when the timestamps earn their place. You attempt the question, you cannot answer it, and you play the four minutes of the recording where the lecturer explained it. That is a replay with a purpose. Playing the whole lecture on day three would take 90 minutes and would revisit the 80 minutes you already understood.

Day seven is when you find out whether the notes are any good. A question you still cannot answer after two attempts usually means the section under it is a summary of what was said rather than an explanation of it; rewrite that section in your own words, from the transcript, and leave the rest alone.

What about the lecture you missed?

The one exception to "never replay in full" is the lecture you were not at. Sheffield's guide is specific: watch it once at normal speed and take notes as if you were in the room, then treat it like any other lecture. The same day workflow applies afterwards, with the difference that the transcript is your first contact with the material rather than a reminder of it, so the structuring step takes longer.

It is worth knowing that recordings do not replace attendance for most students. In a study across all four years of an undergraduate degree, Nordmann and colleagues found that for first year students both attendance and recording use predicted performance, and that recordings helped most as a supplement to attending. Only the strongest students could make up for poor attendance with recordings. If you are in the room, paying attention in lectures is still the cheapest study method available, and the recording is insurance.

What if there is no transcript?

Then the workflow shortens but does not change. Play the recording once, at normal speed, and write headings and questions as you go rather than notes. Pause when the lecturer changes topic and write the heading; pause when a section ends and write the question it answered. It takes the full 90 minutes, which is why a transcript is worth having, but at the end you have the same two pages of headings and questions, and you never play the recording in full again.

Whatever you use for the transcript, get the language right before anything else. Every later step inherits the transcript's errors, and an engine that does not handle your language produces text that looks like a transcript and means nothing.

Where does Notibo fit?

Notibo does steps one to three automatically: it transcribes the recording in 89 languages, writes the headings and a structured summary, and generates question cards you can answer on the day three and day seven schedule. What it does not do is the answering. The retrieval on day three and day seven is still yours, and it is still the part that decides what you remember.

Frequently asked questions

Should I listen to a recorded lecture again before the exam?
Not in full. Replay the two or three passages you marked as unclear, and spend the rest of the time answering questions from your notes. Imperial College's study guide tells students to rewatch in full only if they missed the lecture, because deciding which parts to revisit is itself part of the learning.
How long does it take to process one recorded lecture?
About 30 to 40 minutes the same day for a 90 minute lecture: ten to read and structure the transcript, ten to write questions, ten to answer them once. The reviews on day three and day seven take about ten minutes each. That is under an hour in total, against ninety minutes for a single replay.
Is a recording as good as attending?
No. Nordmann and colleagues found that for first year students both attendance and recording use predicted grades, and that recordings helped most as a supplement to attending. Use the recording to repair the notes from a lecture you attended, and as a fallback for the one you missed.
What if the transcript is full of errors?
Check the language setting first; a Danish lecture transcribed as English is unreadable. Then accept that technical terms will be misspelled and fix them only in the headings and questions. You are not producing a clean transcript, you are producing notes.
Can I just play the recording at double speed?
You can, but it speeds up a method that does not work well at any speed. Sheffield's guide advises watching a missed lecture once at normal speed and taking notes as if you were there. For a lecture you attended, the transcript plus questions replaces the replay altogether.
Why not just listen to it again?
Because a replay is rereading with a pause button, and rereading is one of the weakest study methods there is. In the 2013 review by Dunlosky and colleagues, rereading was rated low utility while testing yourself and spacing your study were rated high. A lecture replay has the same problem in a slower format: the material feels familiar on the second pass, the familiarity feels like knowledge, and the exam finds out otherwise. The universities that provide lecture capture say the same. Imperial College's guide to using lecture recordings tells students to rewatch in full only if they missed the lecture, and adds that the act of deciding which parts to revisit is itself part of the learning.
What do you do the same day?
Five steps, about half an hour, done before you go to bed on the day of the lecture. The same day matters because the transcript makes most sense while you still remember the room, and because the first review is the one that stops the forgetting curve from doing its worst.
What do you do the week after?
The same day pass produces two pages of structured notes with questions and a short list of timestamps. The week after is three short sessions. Day three is when the timestamps earn their place. You attempt the question, you cannot answer it, and you play the four minutes of the recording where the lecturer explained it. That is a replay with a purpose. Playing the whole lecture on day three would take 90 minutes and would revisit the 80 minutes you already understood. Day seven is when you find out whether the notes are any good.

Sources

  1. Using lecture recordings (Imperial College London, Success Guide) (rewatch in full only if you missed the lecture; revisit the parts you did not understand; do not binge in revision week)
  2. How to make the most of lecture capture (University of Sheffield, StudySkills@Sheffield) (summarise rather than transcribe, revisit specific sections within two to three days, watch a missed lecture at normal speed)
  3. Turn up, tune in, don't drop out: the relationship between lecture attendance, use of lecture recordings, and achievement at different levels of study (Nordmann et al., Higher Education, 2019) (attendance and recording use both predicted first year grades; recordings helped as a supplement)
  4. Test-enhanced learning: taking memory tests improves long-term retention (Roediger and Karpicke, Psychological Science, 2006) (answering questions beat restudying on delayed tests)
  5. Improving Students' Learning With Effective Learning Techniques (Dunlosky et al., Psychological Science in the Public Interest, 2013) (rereading rated low utility; practice testing and distributed practice rated high)

About the author

Farhad Ba-Ali

Farhad Ba-Ali builds Notibo in Odense, Denmark. He writes about study methods, memory and note-taking from the questions students send in, and from what the product's own data shows.

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