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.
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.
Ars Technica does something similar and it's a great addition to the overloaded upvote/downvote
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.