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> TikTok's app is the result of designing an app around a recommendation algorithm First time I hear of TikTok in those terms. Could you expand on what that me

by solalf 4y ago

> TikTok's app is the result of designing an app around a recommendation algorithm First time I hear of TikTok in those terms. Could you expand on what that means?

shep101 4y ago
he just did
paulcole 4y ago
I’m very curious how you’ve heard TikTok described in the past. The whole point of TikTok is that you don’t have to follow people or engage with your friends on the platform. You just open it up and it’ll show you videos that you’ll like. Obviously, there is a little bit of “training” involved. Within about 20-40 minutes it really started to zero in on things I liked.
rolisz 4y ago
Here's an article discussing this at length: https://www.eugenewei.com/blog/2020/9/18/seeing-like-an-algorithm https://www.eugenewei.com/blog/2020/9/18/seeing-like-an-algo...
wongarsu 4y ago
The app is designed in a way that basically everything you do results in a strong positive or negative signal for a video that the recommendation algorithm can use. Take Youtube, a video site that added suggestions. If you're logged in, you get dumped on a homepage with an endlessly scrolling list of recommendations. You scroll until a thumbnail or video title catches your eye, you watch that video, might like or comment, then click one of ~10 recommendations. The algorithm gets a positive signal based on what you click and your watch-time, but the negative signal on anything you don't click is incredibly weak. Because you choose what you watch, positive signals are mostly driven by titles, thumbnails and familiarity, and negative signals are rare. As a result, most recommendations are stuff you know or things adjacent to it (people who watch this also watch this), and quickly get boring. The recommendations can't inject novelty or purposefully expand the algorithm's knowledge. Now on Tiktok: You open the app, you get a single video in full screen. Either you scroll on (negative signal) or you watch it until the end (positive), or you let it repeat (very positive). Or you might like or comment. After scrolling on, you get another video in full screen, same game again. The cost of a bad recommendation is low because videos are short and quick to judge, so the algorithm can occasionally give you videos it's uncertain about or that are selected completely randomly. Your reaction will give a signal, no matter what (either you watch till the end or you don't) and as a result the algorithm knows more about you and about the video.
- unityByFreedom 4y ago
  That explains the viewer's side, but what about the publisher/influencer side? How does TikTok decide one video is more suitable than another? My guess is every single video is marked by a human for how much exposure it should get, and if they let something get out that shouldn't, that person is reprimanded.
  - ksdnjweusdnkl21 4y ago
    Just show it to a handful of people, if they liked it show it to more. Keep looping this and good videos go viral, and bad videos don't.
    - saurik 4y ago
      (Essentially using a standard strategy for multi-armed bandit.)
  - scrollaway 4y ago
    > My guess is every single video is marked by a human for how much exposure it should get, and if they let something get out that shouldn't, that person is reprimanded. … Wait what? Why would that be your guess? How is this easier than, you know, anything else?
- ma2rten 4y ago
  I don’t know about other people but I tend to just watch every video until the end because they are so short that I don’t have enough time to decide if I like them or not. Maybe I’m too old for TikTok.
- lordnacho 4y ago
  > Either you scroll on (negative signal) or you watch it until the end (positive), or you let it repeat (very positive). Sounds like this would heavily incentivize items that are immediately catchy. Slow buildup stuff would die in this environment.
  - deleted 4y ago
gloryjulio 4y ago
https://www.ycombinator.com/library/3x-hidden-forces-behind-toutiao-china-s-content-king https://www.ycombinator.com/library/3x-hidden-forces-behind-... If you are really interested, check the yc article in 2016. The algorithm is their bread and butter. They have been doing it for 10 years. What's more amazing to me is that not many ppl are aware of this.

by solalf 4y ago

> TikTok's app is the result of designing an app around a recommendation algorithm First time I hear of TikTok in those terms. Could you expand on what that means?

shep101 4y ago

he just did

paulcole 4y ago

I’m very curious how you’ve heard TikTok described in the past. The whole point of TikTok is that you don’t have to follow people or engage with your friends on the platform. You just open it up and it’ll show you videos that you’ll like. Obviously, there is a little bit of “training” involved. Within about 20-40 minutes it really started to zero in on things I liked.

rolisz 4y ago

Here's an article discussing this at length: https://www.eugenewei.com/blog/2020/9/18/seeing-like-an-algorithm https://www.eugenewei.com/blog/2020/9/18/seeing-like-an-algo...

wongarsu 4y ago

The app is designed in a way that basically everything you do results in a strong positive or negative signal for a video that the recommendation algorithm can use. Take Youtube, a video site that added suggestions. If you're logged in, you get dumped on a homepage with an endlessly scrolling list of recommendations. You scroll until a thumbnail or video title catches your eye, you watch that video, might like or comment, then click one of ~10 recommendations. The algorithm gets a positive signal based on what you click and your watch-time, but the negative signal on anything you don't click is incredibly weak. Because you choose what you watch, positive signals are mostly driven by titles, thumbnails and familiarity, and negative signals are rare. As a result, most recommendations are stuff you know or things adjacent to it (people who watch this also watch this), and quickly get boring. The recommendations can't inject novelty or purposefully expand the algorithm's knowledge. Now on Tiktok: You open the app, you get a single video in full screen. Either you scroll on (negative signal) or you watch it until the end (positive), or you let it repeat (very positive). Or you might like or comment. After scrolling on, you get another video in full screen, same game again. The cost of a bad recommendation is low because videos are short and quick to judge, so the algorithm can occasionally give you videos it's uncertain about or that are selected completely randomly. Your reaction will give a signal, no matter what (either you watch till the end or you don't) and as a result the algorithm knows more about you and about the video.

unityByFreedom 4y ago
That explains the viewer's side, but what about the publisher/influencer side? How does TikTok decide one video is more suitable than another? My guess is every single video is marked by a human for how much exposure it should get, and if they let something get out that shouldn't, that person is reprimanded.
- ksdnjweusdnkl21 4y ago
  Just show it to a handful of people, if they liked it show it to more. Keep looping this and good videos go viral, and bad videos don't.
  - saurik 4y ago
    (Essentially using a standard strategy for multi-armed bandit.)
- scrollaway 4y ago
  > My guess is every single video is marked by a human for how much exposure it should get, and if they let something get out that shouldn't, that person is reprimanded. … Wait what? Why would that be your guess? How is this easier than, you know, anything else?
ma2rten 4y ago
I don’t know about other people but I tend to just watch every video until the end because they are so short that I don’t have enough time to decide if I like them or not. Maybe I’m too old for TikTok.
lordnacho 4y ago
> Either you scroll on (negative signal) or you watch it until the end (positive), or you let it repeat (very positive). Sounds like this would heavily incentivize items that are immediately catchy. Slow buildup stuff would die in this environment.
- deleted 4y ago

gloryjulio 4y ago

https://www.ycombinator.com/library/3x-hidden-forces-behind-toutiao-china-s-content-king https://www.ycombinator.com/library/3x-hidden-forces-behind-... If you are really interested, check the yc article in 2016. The algorithm is their bread and butter. They have been doing it for 10 years. What's more amazing to me is that not many ppl are aware of this.