16 ms·

How TikTok's design makes the algorithm work

67 points by sbuccini 6y ago

teptoria 6y ago
Interesting read, thanks!
exciteabletom 6y ago
I liked the point that algorithms don't have to be user-hostile. Thanks for the read.
hamolton 6y ago
> Before the video is even sent down to your phone by the FYP algorithm, some human on TikTok’s operations team has already watched the video and added lots of relevant tags or labels. Is this confirmed? That's a neat tidbit. Nice article!
- Nextgrid 6y ago
  This is a very nice thing to see as it ensures that only content approved by a human reviewer can be promoted by the algorithm, hopefully reducing the risk that malicious/illegal content goes viral.
  - raxxorrax 6y ago
    Only approved content means mostly boring content that conforms to markets and other ambitions. No illegal content for a social media service from China is a pretty large negative point.
    - yorwba 6y ago
      > No illegal content for a social media service from China is a pretty large negative point. If they allowed illegal content, they'd have been banned even sooner. The best you can hope for is that they do not apply Chinese law outside of China, which seems to be the case, considering they have to make TikTok unavailable in China to avoid people seeing anything that's illegal in China.
      - raxxorrax 6y ago
        The Chinese version is called Douyin and it probably is a completely separate network. The problem with "illegal" is that it is quickly extended to legally questionable. Defending content is not financially viable for any platform, even if you are in the right. In consequence it will be removed. Twitter, Facebook and co currently attempt a regulatory capture and want to actually scrap their legal protections because they now have their censorship algorithm idiots demanded for some time.
- starfallg 6y ago
  This is very likely based on the size of the moderation teams working for TikTok/Bytedance. It's also the reason why TikTok is going to be hard to scale profitably in advanced economies. Chinese staff, especially for work like moderation, is a lot cheaper. Worth nothing that TikTok operations globally is mainly supported by Bytedance staff in China. Very skeptical on how they can achieve splitting the company and launching an IPO without moving most of those jobs moving overseas. If they split off some staff into their own Chinese company owned by TikTok Global based in the US, it doesn't change anything. License from Bytedance to allow TikTok the use the codebase and code also won't fly in an IPO. The only way this makes sense is that TikTok will never IPO, this is merely a delaying tactic until the election year closes.
082349872349872 6y ago
Someone on a different thread asked what new smartphone CPUs would be used for. The answer, according to this article, is gaze tracking the infinite scroll. (Hmm. Part of the idea presented here is that it really doesn't take that long, especially in short-form, to gather less than thirty bits worth of targeting. In a world where "bespoke" is available to everyone, will hipsters have to shift to lauding mass-production to differentiate themselves?)
- pjc50 6y ago
  Wasn't investigating the relationship between mass production and art Warhol's big thing?
abc-xyz 6y ago
TikTok’s recommendation system is absurdly overrated. I tried to make an account where I only watched (in full length)/searched for/liked videos of a specific gender/race/age group.. yet even after liking over a hundred videos, then 100% of the videos they suggested to me were the wrong gender/race/age group. YouTube on the other hand is capable of recommending the correct videos after watching just a couple. Instagram’s recommendations are also far more accurate (although I dislike the fact that Instagram mostly recommend popular users). It’s very easy (and shouldn’t take long) to conduct this experiment, just make sure that the race you target doesn’t represent the majority of the users in your proximity. For instance, if you’re in Norway then try to get TikTok to recommend Asian girls aged 20-35.. sounds like it should be easy, right?
- Polylactic_acid 6y ago
  This seems like an unusual use case. Surely a recommendation system should try to find content that matches the users interests. I'm not sure why anyone would want a recommendation system that looks for age/gender/race as that seems fairly irrelevant to interesting content.
  - dstick 6y ago
    I think the intention behind the OP’s post was to test how quickly you could steer the algorithm in a very specific direction.
    - coolgod 6y ago
      Its such a shame that Tiktok with its massive teenage userbase doesn't have youtube's infamous recommendation system which inadvertently creates pedophilic wormholes.
  - abc-xyz 6y ago
    I’d say there are countless of valid use cases where this is relevant. Maybe you normally live in (or plan to travel to, or just curious about) X country but TikTok is incapable of understanding you’re only interested in videos from there. Maybe you enjoy watching 20-something year old Asian girls dance, maybe you enjoy watching 20-something white guys skateboarding, maybe you enjoy watching guys with sixpack exercise, maybe you enjoy watching party/club videos, maybe you enjoy watching people cook cakes, etc. YouTube and Instagram is easily capable of recommending whatever content you show interest in.. TikTok on the other hand feels like the reddit’s /r/popular experience which simply looks at your location and recommend a list of random stuff that people in same area have shown interest in (and completely fail to integrate your interests into this feed). I’m not saying there’s anything wrong with that, but all this hype about their algorithm makes no sense.
jcynix 6y ago
Very interesting article, including the linked first part. Especially his point in the first part that > It turns out that in some categories, a machine learning algorithm significantly responsive and accurate can pierce the veil of cultural ignorance. Today, sometimes culture can be abstracted. Which now makes me think about where algorithms are culture dependent and where not. Low level algorithms like quicksort definitely are not, but as we get "higher up" towards algorithms which work with user feedback …
- anjc 6y ago
  > ... where algorithms are culture dependent and where not. Low level algorithms like quicksort definitely are not ... Aside on this. In a 1st year CS class I was surprised to learn that half the class had one method to count the number of days in a month (30 days hath September) and the other half had another (using their knuckles). The method a person knew depended on where they grew up, and neither group had heard of the other method. So at least some search algorithms are culturally dependent :)
Kiro 6y ago
I've always said that people complaining about portrait videos don't understand how much more convenient it is to watch. TikTok really takes the one-hand casual video watching to its extreme.
mgraczyk 6y ago
This article is full of interesting ideas and speculation, but I think it gives TikTok a bit too much credit. I don't want to sound overly dismissive, but it's pretty clear reading this that the author has not worked on recommendation or personalization systems recently. The high level description of how he believes TikTok works is probably accurate (I don't work there so I can only speculate), but it's not unique to TikTok. Also most of the details are probably not accurate. Some examples: > For its algorithm to become as effective as it has, TikTok became its own source of training data. ^This is true of nearly every recommendation system. > If you click into a text post by someone on Facebook but don’t comment or like ... That negative sentiment is difficult to capture You can do the same thing with comments that he claims TT does with video (dwell time threshold feature) > As you scroll up and past many stories, the algorithm can’t “see” which story your eyes rest on. I don't work at Twitter, but I doubt that matters very much. Also regarding "negative sentiment" feedback from users. TikTok does not have a UI tool to say "I don't like this", but other apps do. For example, you can ask Instagram to "show me fewer posts like this". I agree with the claim that the "one thing at a time" UI is nice for the user in a lot of ways. But as a person who builds these things, I don't think this makes much of a difference for machine learning.
- 082349872349872 6y ago
  > dwell time threshold feature For me at least, tiktok.com is an infinite scroll.
  - hombre_fatal 6y ago
    Though note that it's no mystery which video you're looking at, thus endless scroll still often has the same beneficial one-at-a-time characteristics that the article celebrates. In fact, imgur's desktop website comes to mind as the rare design pattern where you can (or, could, back when it was only gifs) consume the content in a gallery view where the application doesn't know what holds your attention.
- rsa25519 6y ago
  > TikTok does not have a UI tool to say "I don't like this", but other apps do. For example, you can ask Instagram to "show me fewer posts like this". Press and hold on TikTok shows a popup for this.
fuzzybear3965 6y ago
Boy, can this guy write, or what? Eugene Wei's content always enraptures me. Really captivating stuff.
freebee16 6y ago
I never found the recommended content on TickTock very good. It really does seem like it is geared to a certain kind of teenager. Chinese video recommendation apps on the other hand (e.g. douyin, xiaohongshu, Kuaishou, Xigua) are excellent.

67 points by sbuccini 6y ago

teptoria 6y ago

Interesting read, thanks!

exciteabletom 6y ago

I liked the point that algorithms don't have to be user-hostile. Thanks for the read.

hamolton 6y ago

> Before the video is even sent down to your phone by the FYP algorithm, some human on TikTok’s operations team has already watched the video and added lots of relevant tags or labels. Is this confirmed? That's a neat tidbit. Nice article!

Nextgrid 6y ago
This is a very nice thing to see as it ensures that only content approved by a human reviewer can be promoted by the algorithm, hopefully reducing the risk that malicious/illegal content goes viral.
- raxxorrax 6y ago
  Only approved content means mostly boring content that conforms to markets and other ambitions. No illegal content for a social media service from China is a pretty large negative point.
  - yorwba 6y ago
    > No illegal content for a social media service from China is a pretty large negative point. If they allowed illegal content, they'd have been banned even sooner. The best you can hope for is that they do not apply Chinese law outside of China, which seems to be the case, considering they have to make TikTok unavailable in China to avoid people seeing anything that's illegal in China.
    - raxxorrax 6y ago
      The Chinese version is called Douyin and it probably is a completely separate network. The problem with "illegal" is that it is quickly extended to legally questionable. Defending content is not financially viable for any platform, even if you are in the right. In consequence it will be removed. Twitter, Facebook and co currently attempt a regulatory capture and want to actually scrap their legal protections because they now have their censorship algorithm idiots demanded for some time.
starfallg 6y ago
This is very likely based on the size of the moderation teams working for TikTok/Bytedance. It's also the reason why TikTok is going to be hard to scale profitably in advanced economies. Chinese staff, especially for work like moderation, is a lot cheaper. Worth nothing that TikTok operations globally is mainly supported by Bytedance staff in China. Very skeptical on how they can achieve splitting the company and launching an IPO without moving most of those jobs moving overseas. If they split off some staff into their own Chinese company owned by TikTok Global based in the US, it doesn't change anything. License from Bytedance to allow TikTok the use the codebase and code also won't fly in an IPO. The only way this makes sense is that TikTok will never IPO, this is merely a delaying tactic until the election year closes.

082349872349872 6y ago

Someone on a different thread asked what new smartphone CPUs would be used for. The answer, according to this article, is gaze tracking the infinite scroll. (Hmm. Part of the idea presented here is that it really doesn't take that long, especially in short-form, to gather less than thirty bits worth of targeting. In a world where "bespoke" is available to everyone, will hipsters have to shift to lauding mass-production to differentiate themselves?)

pjc50 6y ago
Wasn't investigating the relationship between mass production and art Warhol's big thing?

abc-xyz 6y ago

TikTok’s recommendation system is absurdly overrated. I tried to make an account where I only watched (in full length)/searched for/liked videos of a specific gender/race/age group.. yet even after liking over a hundred videos, then 100% of the videos they suggested to me were the wrong gender/race/age group. YouTube on the other hand is capable of recommending the correct videos after watching just a couple. Instagram’s recommendations are also far more accurate (although I dislike the fact that Instagram mostly recommend popular users). It’s very easy (and shouldn’t take long) to conduct this experiment, just make sure that the race you target doesn’t represent the majority of the users in your proximity. For instance, if you’re in Norway then try to get TikTok to recommend Asian girls aged 20-35.. sounds like it should be easy, right?

Polylactic_acid 6y ago
This seems like an unusual use case. Surely a recommendation system should try to find content that matches the users interests. I'm not sure why anyone would want a recommendation system that looks for age/gender/race as that seems fairly irrelevant to interesting content.
- dstick 6y ago
  I think the intention behind the OP’s post was to test how quickly you could steer the algorithm in a very specific direction.
  - coolgod 6y ago
    Its such a shame that Tiktok with its massive teenage userbase doesn't have youtube's infamous recommendation system which inadvertently creates pedophilic wormholes.
- abc-xyz 6y ago
  I’d say there are countless of valid use cases where this is relevant. Maybe you normally live in (or plan to travel to, or just curious about) X country but TikTok is incapable of understanding you’re only interested in videos from there. Maybe you enjoy watching 20-something year old Asian girls dance, maybe you enjoy watching 20-something white guys skateboarding, maybe you enjoy watching guys with sixpack exercise, maybe you enjoy watching party/club videos, maybe you enjoy watching people cook cakes, etc. YouTube and Instagram is easily capable of recommending whatever content you show interest in.. TikTok on the other hand feels like the reddit’s /r/popular experience which simply looks at your location and recommend a list of random stuff that people in same area have shown interest in (and completely fail to integrate your interests into this feed). I’m not saying there’s anything wrong with that, but all this hype about their algorithm makes no sense.

jcynix 6y ago

Very interesting article, including the linked first part. Especially his point in the first part that > It turns out that in some categories, a machine learning algorithm significantly responsive and accurate can pierce the veil of cultural ignorance. Today, sometimes culture can be abstracted. Which now makes me think about where algorithms are culture dependent and where not. Low level algorithms like quicksort definitely are not, but as we get "higher up" towards algorithms which work with user feedback …

anjc 6y ago
> ... where algorithms are culture dependent and where not. Low level algorithms like quicksort definitely are not ... Aside on this. In a 1st year CS class I was surprised to learn that half the class had one method to count the number of days in a month (30 days hath September) and the other half had another (using their knuckles). The method a person knew depended on where they grew up, and neither group had heard of the other method. So at least some search algorithms are culturally dependent :)

Kiro 6y ago

I've always said that people complaining about portrait videos don't understand how much more convenient it is to watch. TikTok really takes the one-hand casual video watching to its extreme.

mgraczyk 6y ago

This article is full of interesting ideas and speculation, but I think it gives TikTok a bit too much credit. I don't want to sound overly dismissive, but it's pretty clear reading this that the author has not worked on recommendation or personalization systems recently. The high level description of how he believes TikTok works is probably accurate (I don't work there so I can only speculate), but it's not unique to TikTok. Also most of the details are probably not accurate. Some examples: > For its algorithm to become as effective as it has, TikTok became its own source of training data. ^This is true of nearly every recommendation system. > If you click into a text post by someone on Facebook but don’t comment or like ... That negative sentiment is difficult to capture You can do the same thing with comments that he claims TT does with video (dwell time threshold feature) > As you scroll up and past many stories, the algorithm can’t “see” which story your eyes rest on. I don't work at Twitter, but I doubt that matters very much. Also regarding "negative sentiment" feedback from users. TikTok does not have a UI tool to say "I don't like this", but other apps do. For example, you can ask Instagram to "show me fewer posts like this". I agree with the claim that the "one thing at a time" UI is nice for the user in a lot of ways. But as a person who builds these things, I don't think this makes much of a difference for machine learning.

082349872349872 6y ago
> dwell time threshold feature For me at least, tiktok.com is an infinite scroll.
- hombre_fatal 6y ago
  Though note that it's no mystery which video you're looking at, thus endless scroll still often has the same beneficial one-at-a-time characteristics that the article celebrates. In fact, imgur's desktop website comes to mind as the rare design pattern where you can (or, could, back when it was only gifs) consume the content in a gallery view where the application doesn't know what holds your attention.
rsa25519 6y ago
> TikTok does not have a UI tool to say "I don't like this", but other apps do. For example, you can ask Instagram to "show me fewer posts like this". Press and hold on TikTok shows a popup for this.

fuzzybear3965 6y ago

Boy, can this guy write, or what? Eugene Wei's content always enraptures me. Really captivating stuff.

freebee16 6y ago

I never found the recommended content on TickTock very good. It really does seem like it is geared to a certain kind of teenager. Chinese video recommendation apps on the other hand (e.g. douyin, xiaohongshu, Kuaishou, Xigua) are excellent.