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TikTok reveals details of how its algorithm works

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Re: TikTok reveals details of how its algorithm works

#131

I find that it takes device into account very interesting. What does me using an iPhone XS vs a Samsung Note vs a generic cheap Android phone say about me? I wonder if ends up being a proxy for income, age, or gender...

oh its 1000% a proxy for income. No doubt about it.

Re: TikTok reveals details of how its algorithm works

#132

TikTok is like a highly compressed version of YouTube. YouTube incentivizes creators to make artificially long videos, resulting in a huge amount of filler. So you get a lot of videos where you can skip the first 20%+ and not miss anything. The content is buried and spread out. 1 minute of content surrounded by 9 minutes of filler. TikTok removed those 9 minutes, so it feels very refreshing in that respect. There's n…

> incentivizes creators to make artificially long videos

One of the reasons I use a FF addon to make the default speed of all youtube videos 1.5X. So few v-bloggers are succinct and fluid enough to have to listen at 1X.

Re: TikTok reveals details of how its algorithm works

#133
post #128

Earlier quoted context omitted.

I wish youtube was better in this regard. The videos it shows me just keep getting more and more focused on what it knows I'm interested in, to the point that it's boring. I discover new things to watch through reddit instead.

I wish the recommendation algorithm had knobs users could manipulate. eg - show me things that have - reduce the weight of popular channels - don't send me into a political content feedback loop - prefer to show me short videos - show me something wildly outside my tastes every now and then I just got the Youtube Music app and it had very crude music recommendation options. You have to pick from a pre-selected list o…

The biggest problem in user-facing software right now is that product managers assume they + an algorithm can figure out what you want based on behavior, and that you shouldn't have any direct input in that. The best you'll usually see is an "i don't like this" button.

Spotify sidesteps some of this by just giving you a bunch of different algorithms feeding different playlists, so at least there are options, but I miss having settings to tweak to gain more control, or to point it in the right direction better.

Re: TikTok reveals details of how its algorithm works

#134

To be fair, the algorithm they told is mostly what we would have perceived, knowing if that is Machine Learning driven. Although, I am quite intrigued what they would be showcasing in their "transparency centers". If they show what extent their data can be utilized. and not simply a simulation of the ML stuff.

I think it's interesting how they took the warnings on creating feedback loop "bubbles" and social media addiction causes and used that as their business model.

It's the logical result of where we are going as a society.

World of Warcraft may not have started out as a Skinner Box. But they realized what they had and used it to their advantage. The result is that all games today are casino-ified. Lootboxes, microtransactions, abstracted currency, etc. It all comes from Vegas.

TikTok and apps like Robinhood are the bleeding edge of this.

https://www.forbes.com/sites/sergeiklebnikov/2020/06/17/20-y...

Turning the stock market into a slick slot machine with all the same feedback and nudges. It's sickening, but not surprising.

Re: TikTok reveals details of how its algorithm works

#135

Earlier quoted context omitted.

What surprises me is all of what you've said is the way pretty much all recommenders work - YouTube, Facebook, Twitter, etc. will all be doing this. Yet people don't spend hours per day browsing tweets. What is it about tiktok which is so much more effective?

Facebook and Twitter are social-graph subscription-based services. TikTok just gives recomendations without subscriptions while knowing nothing about my social graph.

Well, except for follows, right?

But yeah, it appears (from TikTok's success) that the social graph may not be particularly useful for content-based recommendation (which really, we should probably have realised given the existence of Google).

Re: TikTok reveals details of how its algorithm works

#136
post #59

Earlier quoted context omitted.

I actually think it's got much more to do with the training data. Given that you are watching a video, you need to either swipe away from it, or finish watching it. This provides either a 1 or 0 for the video classification model. The important contrast here is with FB/IG feed where you can scroll aimlessly without engaging, leaving you with perhaps 1 engagement out of 10 (or whatever). The attached doc suggests that…

Reducing engagement data to 0/1 would lose a lot of precious data, it treats getting 50s through a 1m video worse than watching the whole of a 5s clip, and watching a 2s clip the same as watching a 2s clip on loop 20 times because it's so incredible. Given the point of the app is to get people on it for a long time, it would make much more sense to track number of seconds watched and train to maximize that.

Like, this probably isn't how I would implement such a system. But it's an important explanation for how TikTok does such good recommendations.

It's a HN comment, not an in-depth blog post :)

Re: TikTok reveals details of how its algorithm works

#137
post #8

It's a (seemingly) pretty simple matter of keeping track of how long someone looks at a video, and optimizing to show them videos they'll spend a long time looking at. It's pretty powerful too, I spend much more time looking at TikTok than any other digital content aggregator (to the extent I had to delete it from my phone). They also do some things like sprinkle in random fresh videos, potentially unrelated to your…

> they'll get paid directly from TikTok, rather than needing to source a third party company to sponsor them. So like, what Adsense did to the internet and exactly what Youtube is trying to undo.

That was the overall trend in YouTube since 2013 that makes sense for YouTube as a business but makes me a bit sad as a user. When they started to split up YouTube picked out the top, corporate friendly creators to let advertisers pick and choose how to target their (eventually content self-censoring) advertising money rather than offering YouTube as a whole bundle and letting the keyword auction do its work opaquely. This creates to inevitable incentive problem down the road we're all witnessing now such as asymmetrical content id powers, no monetization for grassroot creators, content censorship etc.

Re: TikTok reveals details of how its algorithm works

#138
post #11

Earlier quoted context omitted.

I've also found that TikTok does a good job of throwing in unexpected videos to test the waters of what the user is interested in. This diversity is one of my favorite things about it.

A common comment I see on Tiktok videos is something like "I've finally made it to [niche interest] tiktok", it's something I've experienced myself when the algorithm started showing me videos from the crew on cargo ships as they talk about their favorite ports to dock at, or their experience going through E.G the Panama Canal. I don't know any other platform that emergently figures out that I have an interest in int…

The exact same thing happens for me on YouTube, although I guess YouTube doesn't start with an auto-playing random sequence of videos to quick-start the search for videos you find interesting. Still though, I end up in very odd niches that I never specifically searched for.

Re: TikTok reveals details of how its algorithm works

#139

TikTok is like a highly compressed version of YouTube. YouTube incentivizes creators to make artificially long videos, resulting in a huge amount of filler. So you get a lot of videos where you can skip the first 20%+ and not miss anything. The content is buried and spread out. 1 minute of content surrounded by 9 minutes of filler. TikTok removed those 9 minutes, so it feels very refreshing in that respect. There's n…

I watch a lot of YouTube and haven't really noticed any artificially long videos in my bubble of channels. I agree that intros are annoying (I have no idea why people do them), but other than that... it's just the usual video stuff. The nature of the format is that a one page blog post becomes a 10 minute video. People talk slower than they read, so it's somewhat unavoidable. There are also YouTubers that are really…

I don't find much filler among the areas of interest that I specifically follow on YouTube (some of that of course being due to my own selection of who to subscribe to), but I do find that filler on YouTube when I'm searching for some other instructional information on Google.

Re: TikTok reveals details of how its algorithm works

#140

Earlier quoted context omitted.

> YouTube incentivizes creators to make artificially long videos, resulting in a huge amount of filler. Given how popular obnoxious jump cuts are on YouTube, I would assume this wasn't the case. What part of YouTube incentivizes this? I always attributed the increased intros/outros/ad spot/filler lengths to the general trend of YouTube getting more "professional" than it did 10 years ago.

Historically YouTube would downregulate short videos in their algorithms. The cutoff was 10 minutes, if I remember correctly. So the biggest content creators got used to stretching out any video to at least 10 minutes. I think YouTube has relaxed that a bit recently. Which is funny in the greater historical context, because in the early days of YouTube you couldn't upload videos longer than 10 minutes. EDIT: As an as…

I believe the 10 minute thing is because YouTube at some point let you include mid-roll ads if your video was longer than 10 minutes.
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