The science and purpose behind TikTok's algorithms have been revealed in a leaked document shown to the New York Times. BackStory: and is, IMHO, the most addictive of all the social media platforms. If you've never been on TikTok, it serves up an endless stream of very short videos (max length is 3 mins, but the majority are less than 1 min). The algorithms figure out your preferences within a very short period of time because of the intensity of signals they capture in a concentrated period. TikTok now has a billion active users every month When you listen to Spotify or watch Netflix, it takes hours of attention before the platform figures out that you like soul or Succession. But with TikTok, it takes 15 to 20 minutes before the app knows your musical, political and sexual tastes, even your state of mind. WhichMeansThat: The leaked document shown to the NY Times explains that in the pursuit of the company’s “ultimate goal” (growth of daily active users), it has chosen to optimize for two closely related metrics in the stream of videos it serves: “retention” (whether a user comes back to the same type of content) and “time spent.” (how long they look at a particular video relative to videos from other themes) Ultimately, TikTok wants to keep you there as long as possible. Which means that the experience is often described as an addiction. The document says watch time isn’t the only factor TikTok considers. The document offers a rough equation for how videos are scored, in which a prediction driven by machine learning and actual user behaviour are summed up for each of three bits of data: The document also illustrates in detail how the company tweaks its system to identify and suppress “like bait” (videos designed to game the algorithm by explicitly asking people to like them), and how the company thinks through more nuanced questions. likes, comments and playtime. TikTok is not like the other social media platforms. Facebook, Instagram, Twitter et al rely on a user's 'connections' or list of 'friends' to serve up content. TakeAway: TikTok is different because it does not rely on knowing who your friends are when deciding what content to put in front of you. Instead, the TikTok algorithms figure out exactly what makes you tick based on what’s going on inside your head (which can be the secret interests that you don’t share with your besties). The AI is extremely adept at working out what you really want to see and then feeding it to you. But more than that, the algorithms also recognise that a user can soon get bored with seeing the same stuff on a continuous loop. So the algorithms will start to test out related but different content to see if you like that and to keep you interested. A recent Wall Street Journal report demonstrated how TikTok relies heavily on how much time users spend watching each video to steer them toward more videos that will keep them scrolling. It is this process that causes concern because it can sometimes lead young viewers down dangerous rabbit holes, in particular toward content that promotes suicide or self-harm, problems that TikTok says it’s working to stop by aggressively deleting content that violates its terms of service. “We’re the product. Our attention is the product being sold to advertisers." Justin Rosenstein (The Social Dilemma) TikTok's recipe for getting you hooked Based on observational analysis and the details from the leaked documents, here are the top 5 ways in which the TikTok algorithms keep you coming back for more. 1. Highly Personalised Feed All social media platforms have a recommendations or suggestions section where they can nudge you towards content that the algorithms "think" you'll like. On TikTok, this is called the "For You" page. But the reason why TikTok is different is in the way that they personalise the experience for users. Other social media platforms, like Facebook, Instagram, Linkedin and Twitter base their recommendations on your friend or follower lists. The people that you know and follow are used to influence the suggested content. But TikTok doesn't do this. Instead, they personalise a user's For You page with content that is personalised based on the user's tastes. The more a user lingers and watches certain content, the more that TikTok will feed them with more of the same. TikTok's goal is to get the user locked into a loop of continuous scrolling. 2. Immediate content From the moment the user opens the app, TikTok starts playing a continuous loop of short video clips. There is no login process. The user does not waste time deciding what to look at first or navigating to a home page. The content is instant and immediate. 3. Videos are shown on an endless loop Most social media platforms let you view a certain post and then scroll further. For example, Netflix offers up a pause before the next episode starts playing automatically. Where TikTok is different is that it uses a smart strategy of looping videos again and again. Interestingly, in the Chinese version of TikTok (called Douyin), the Government have introduced restrictions as part of its Big Tech Crackdown. One of them is the introduction of mandatory breaks every 5 minutes or so. This means that Douyin must pause the continuous content feed to break the "lock-in" of continuous scrolling. 4. Quick and short content Tiktok content has a maximum duration of 3 minutes. However, the majority of video shorts are less than a minute and mostly run between 15 and 30 seconds. It doesn't sound long, but that is the magic for TikTok. Just like Twitter when it introduced the 140 character tweet, TikTok has made a virtue out of brevity. The psychology is really smart; the human brain can easily lose track of time. The thought of (only) watching a handful of 15-second videos will seem like it's no time at all when in reality it is very easy to burn 15-20 minutes watching a continuous stream of distracting material. 5. Redefining the way we consume music TikTok has deals with the largest music publishers in the industry. This allows TikTok to list current and trending music from headline acts for users to create video content with. As a result, users add short clips of trending music to their videos, even if the video has nothing to do with the song. This has proven to be a highly effective way for established artists to promote their music. And also opens the door for unknown artists to establish themselves. The point is that TikTok uses music as a key signal for engagement. Popular tracks are used over and over again and have the same effect as turning the radio up when a favourite song comes on the radio. Related Sources of Insight and Information , by the New York Times How TikTok reads my mind by the Seattle Times I need my girlfriend off TikTokI need my girlfriend off TikTok I need my girlfriend off TikTok, , by Repeller The TikTok algorithm knew my sexuality better than I did , by International Business Times Social Media addiction may increase suicide rates amongst adolescents , by Wiser! Newsletter The Attention Economy This article was first posted on the Wiser! Newsletter.