# [Personal Experiment] Training YouTube's Algorithm

I listen to YouTube music every day. I created a new Google account three weeks ago. I've watched nothing but music and dancing on it. Whenever it recommends a non-music non-dancing video I immediately click "Don't recommend channel"[^1].

[^1]: There are two ways to train YouTube to recommend videos: you can "like" them and you can watch them. I use these buttons as normal, clicking "like" only on exceptional videos I want to promote. There are several ways to train YouTube to not recommend videos: you can not watch them, you can "dislike" them, you can click "Not interested", you can click "Don't recommend channel" and you can click "Report". At first I used YouTube's "Not interested" button but quickly switched to "Don't recommend channel" because it resulted in better recommendations. I don't like clicking "dislike" and "Report" for channels I don't want to see because most videos I don't want to watch do produce quality content.

If you you opened my YouTube account right now you'd see 509 recommendations on the home page. 487 would be for music and dancing. 22 would be things I'm not interested in. Below are YouTube's 22 non-musical recommendations:

- Unboxing Violin and Testing
- 不要随便让老师唱歌跳舞，搞不好他们是被教育事业耽误的明星！
- 如何保護總統生命安全？前美國特勤局特務：「我們的任務就是站在威脅與目標之間」｜科普小知識｜GQ Taiwan
- L'équipe du Togo - 60 minutes avec Kheiron
- sony's lead graphic designer coming up with the PS5 logo
- The Engoodening of No Man's Sky
- What is an Exoplanet Documentary - Planets Beyond our Solar System
- Rockman 3 – Dr. Wily no Saigo!? (FC)
- NLE Choppa - Cottonwood (Official Trailer)
- YOU is a weird show...  (Alex Meyers channel)
- Safiya & Tyler's Wedding Highlight Film
- Martin Lawrence Finally Responds To Tisha Campbell Accusations: None Of That Was True - CH News
- True Facts: Mating Dance of the Ostrich
- 5 Sikretong Video Ng NASA Na Nabunyag
- Nanatsu no Taizai 3ª Temporada EPISÓDIO 13 LEGENDADO PT BR
- Weathering With You [Official English Dub Trailer - GKIDS] - January 15
- 【Stanley】海克斯閃現福利熊熊！各種閃現外翻！5/0/10鬼神一般的戰績！原來是上路福利熊啊我還以為是輔助呢！改名以後戳仔大幅下降？成為了勇於認錯的韓服Nice 玩家 +1 [This is a Let's Play]
- Star Wars: The Last Jedi - Training for the Last Jedi
- r/TIHI | TeeHee
- 韓國女生的台灣網咖旅館一日求生挑戰
- The Hobbit with Lightsabers
- When an Imperial Major Didn't Recognize Darth Vader(Canon) - Star Wars Comics Explained

Most of these are understandable errors at personalization. The violin unboxing makes sense because I listen to lots of violin music. The *Star Wars* and anime stuff makes sense because I watch "Star Wars Anime Opening" videos. "不要随便让老师唱歌跳舞..." is dancing-related. I think the movie trailers come from the fact that some of the music videos I watch take the form of movie clips. I was surprised by the science recommendations until I realized it's not difficult to infer that someone who listens to AIVA-generated music over-and-over again (among similar things) might be interested in science. The wedding highlight film could be related to the wedding dance videos I enjoy.

The videos in Chinese, Spanish and Japanese make sense because I listen to music in these languages. When I first created my account it recommended a lot of news, videogames and comedy (among other things). The foreign language news, videogames and comedy are generic recommendations speakers of these languages. If I click "Don't recommend channel" enough times they'll probably go away like they (kinda) do in English. I don't know exactly[^2] where the French and Filipino videos came from but I expect the same goes for them too.

[^2]: I regularly get recommendations to watch videos in languages I don't speak. This could be because many of the Chinese instrumental music videos I watch have half-Chinese half-something-else titles. (Or Japanese *rōmaji* + Spanish as in the case of "Nanatsu no Taizai 3ª Temporada EPISÓDIO 13 LEGENDADO PT BR".) It could be that once you regularly watch videos in four different languages the algorithm decreases the importance of "language" as a feature. YouTube could be performing a Bayesian hyperparameter search and this is part of its exploration phase. Maybe YouTube recommends a small number of foreign language videos to everyone.

This leaves 5 truly impersonal recommendations[^3].

[^3]: They could be true shots in the dark by YouTube's algorithm or stem from some deep correlation like as demographic profiling. For the sake of this analysis, all that matters is they're not effectively personalized.

- sony's lead graphic designer coming up with the PS5 logo
- The Engoodening of No Man's Sky
- YOU is a weird show...
- Martin Lawrence Finally Responds To Tisha Campbell Accusations: None Of That Was True - CH News
- r/TIHI | TeeHee
  
To summarize:
- 97% of what YouTube shows me is under my control.
- 2% is reasonable but incorrect generalizations from my behavior.
- 1% is generic and completely out of my control.