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Field notesfrom a measured library

What measured videos taught us

We score YouTube videos on how much of the runtime actually delivers. These are the patterns that showed up once there were enough of them to count.

Median padding 36% median start of the useful part 0:47 recalculated 19 Oct 2026

  1. Article1 Sep 20266 min

    Where our numbers come from, and where they do not apply

    Nine places where the measurements on this site stop being trustworthy, written down in one page so they do not have to be rediscovered one argument at a time.

  2. Data report1 Sep 20266 min

    Shelf life: how long the material in a video stays true, by subject

    Measured shelf life runs from 84.8 in science to 37.9 in tech news — a 47-point gap. Runtime does not predict it and neither does difficulty. Subject does.

  3. Data report1 Sep 20266 min

    Does a longer video teach you more? We checked, and the answer is yes

    Measured depth rises by 31 points from the shortest videos to the longest, holds inside every subject we can test, and buys less usefulness than you would expect.

  4. Article1 Sep 20264 min

    Do you need an account to use Gistil? Mostly, no

    Reading a measurement we already have takes no account. Asking for a video nobody has measured yet does. Here is exactly where the line sits, and why it is there.

  5. Data report1 Sep 20267 min

    A chapter list tells you where things are, not which one is worth watching

    Section by section across the library. The parts a chapter list would call content vary by 34 points inside a single video, and length barely predicts which is which.

  6. Article26 Aug 20265 min

    How to build a watch-later list you actually finish

    The list keeps growing because saving is free and watching is not. One rule, applied at the moment you save, fixes most of it.

  7. Data report26 Aug 20266 min

    The shape of a YouTube video: every value curve overlaid

    Average measured value climbs fast, holds through the middle two-thirds of a video, then falls sharply near the end. Here is the curve, averaged across the library.

  8. Article26 Aug 20265 min

    How to tell a good tutorial from a bad one in thirty seconds

    Six signals readable from the page before you commit any time, each tied to something we can actually measure across the library rather than a hunch.

  9. Article26 Aug 20266 min

    How to skip to the part of a YouTube video that actually matters

    Five ways to find the useful part of a video without watching the setup, ranked from the one everybody already tries to the one that works before you press play.

  10. Article26 Aug 20265 min

    How to search inside a long video without watching the whole thing

    Browser search only reaches the text on the page, not what's said. Chapters, comments, and the written record of the video each cover a different gap.

  11. Data report26 Aug 20266 min

    Runtime is a useless filter: longer videos carry less padding, not more

    Padding falls from 45% under ten minutes to 28% over an hour, and measured value rises the same way. Picking the shorter video is, on average, backwards.

  12. Article26 Aug 20265 min

    Is watching at 2x speed actually helping you learn?

    Speed compresses a video uniformly, filler and substance alike. Where doubling the speed helps, where it quietly breaks comprehension, and what it does not fix.