Awhile back I started using a video's 'like' button simply as a mechanism by which I could tell if I had watched something before since I did get repeat recommendations. Then, if I clicked a recommended video again later, I'd know I had already seen it. Over time, as far as I could tell, YT stopped recommending videos I'd seen before as there were fewer and fewer videos I would check out that I had already seen.

May also be attributed to something else, or I'm getting old, but it seems to have been a fortunate outcome.

inject those two styles into YT website:

    a #video-title { color: red !important;}
    a:visited #video-title { color: black !important;}

They have two options under the triple dot menu (at least on Android feed) that you are not interested in this video or this channel.

May help curate once you start getting those recommendations.

I once watched a few videos about US politics. After that YouTube just kept spanning half my recommendations with vids about USpol. While they were addicting, they didn't really interest me. I then took the effort to flag tem as 'not interesting' (about 3x, refreshing the browser) and it works, I have gotten very few recommendations about that since then.

Then you cut out videos you were interested in the first place.

When it asks you why you're not interested, one of the options is "I've already watched this video".

I used to do that, but it was a lot of work & I didn't notice an improvement to the search results.

I experienced exactly the same. I suspect that since they're optimising for engagement, already having watched a video is some indication that you'll engage with it again.

Also, if a video thumbnail/title displays on my screen and I don't click it, it is a sign of disinterest. Stop suggesting videos I have repeatedly scrolled past. Use the lack of engagement as a feature.

Once I tried disliking or dismissing a video as enforced dislike. Then it said "ok disengaging the entire category" and I was like wtf no. That's not at all what I wanted. And there was no way to undo. So its frustrating trying to teach those algorithms things I don't like.

It was on google somewhere. It was like I wanted to dislike a particular author or that particular programming language they were talking about, but took it as me not wanting to hear about anything technological ever again. It was frustrating as heck.

This option would single-handedly fix their completely broken music recommendation algorithm that only seems to auto-play the same 5 or so songs that I recently listened to and thumbs-upped.

I get the same behavior, only I've never thumbs-upped anything.

amen! I wish you could crank up exploration cf. exploitation in your settings or something

It would be cool in general if recommendation algorithms or search algorithms were more customizable. I would imagine you could put some code into your settings that controls which recommendations you see. The platform, like YouTube in this case, could compute features that enable different kind of recommendation algorithms. There could be communities of people who tinker with this and share their recommendation algorithms.

Steam added this feature recently (https://store.steampowered.com/recommender/ lets you add weights for "niche/popular" and "older/newer") and I've never had so much fun browsing a store. I hope other platforms take note

* Except for music.

Don't ever recommend videos from 9 years ago please.

This is the part I don't understand, how is Google doing so bad at this. You get slightly better experience if you use Chrome. It (on purposely?) keeps asking you to click 3 buttons to play a video Edge, and won't even show comments.

Our tastes are so different. I'd much rather watch a great video from 2005 than a good one from 2020. I'm irritated by the recommendation algorithms pushing new content. Why would I care whether the video was published last night or last year?

Yes, recommendation should be personalized anyway, so you can get videos from 9 years ago and I don't.

If e.g. you want political thinking in current events than you'd probably value recent videos more.

If you wanna see a great video on some obscure implementation detail of some electronics gear from the soviet era it doesn't really matter if it was uploaded a year ago or 8 years ago.

What I mean is it displays a button to click after I clicked play on video when I use Edge, which is my main drive nowadays. And the comments are not displaying. It cannot be only my experience I hope :S so I get downvoted because my taste not liking old videos :/