Didn't Slashdot have multiple dimensions, a post could be "+5, insightful" or "-3, off topic".
If you squint you could say the same about emoji reactions on Facebook and probably other platforms, this post got 5 :heart and 2 :scary reactions. They don't have a visible one for relevance but presumably the reactions feed into one behind the scenes.
I'm not sure any of these have been shown to be clearly superior to the Reddit/HN approach of a single up/down vote.
I will die on this hill that Slashdot moderation was the best I've used. It made moderation or voting a privilege and not a right so I think people took it seriouisly.
Slashdot comments could never go below -1 (or above +5). Also, moderation wasn't an "everyone votes" thing, moderators were picked semi-randomly and if you got picked, you could only place 5 votes. If you voted and the posted a comment on the same topic all of your moderations would go away.
There was also Meta Moderation where you'd randomly get shown a handful of comments and votes on those comments and you would be asked to judge whether the votes were fair or not. Supposedly those votes would affect your likelihood to get tapped for moderation again.
It would only show one adjective, but the ordering was kind of funny. If someone moderates your comment as a troll but enough people marked it with positive votes, you'd get the coveted "+5 Troll" badge.
I think Slashdot's system was vastly better, but it had different goals.
Social media needs counters that never stop going up, and buttons that are always available for people to reactivity click and express dis/approval.
Slashdot wanted a moderation system and they got one. The moderation points, categories, meta-moderation, comment filtering, it all shows someone was really thinking about what they system was trying to accomplish.
Facebook is beyond useless when it comes to constructive discussions. For all practical purposes it counts even laughing or angry reactions the same way as a simple like and there is no dislike. The very real effect is the current information/trust crisis where even if someone were to patiently explain for the 1000th time that no, COVID is not a hoax or whatever the current ridiculous stupid shit is currently pushed, a newer irrelevant comment will be displayed with the explanation buried deep somewhere.
I think this is a really interesting question as I loved Slashdot's moderation, but I wonder if it results in less engaging (ie less toxic) behavior. Good question ... fartcannon!
I think that at the time when Slashdot slid from mainstream as a discussion platform, the top complaint was that the site's moderators were deciding the posts that got to the front page. Only after Digg and Reddit captured a lot of their original audience, did Slashdot introduce the "firehose" concept, which showed all submissions, before being vetted by the mod team.
Until then the process was that someone would submit a post, someone from the mod team would review (and, maybe edit it) and only then it got to the front page. This, in my opinion, allowed for better quality, despite some of the biases the mod team showed. The community was adamant that it should be in charge of what makes it to the front-page and in this regard Digg and reddit were doing it better, so Slashdot became less and less relevant.
If you squint you could say the same about emoji reactions on Facebook and probably other platforms, this post got 5 :heart and 2 :scary reactions. They don't have a visible one for relevance but presumably the reactions feed into one behind the scenes.
I'm not sure any of these have been shown to be clearly superior to the Reddit/HN approach of a single up/down vote.