Earlier quoted context omitted.
the best thing here is active moderation weeding out the most negative and unhelpful comments, trying to keep the discussions civil. It's hard and requires a lot of effort but HN is a good example of what it can look like at best.
It could be better. Slashdot has (or maybe had, I haven't checked in a while) a way of associating votes with tags. So upvotes could be tagged "insightful" or "funny" or whatever, and downvotes tagged "flamebait" or "off-topic" or others. Especially for downvotes I would often be interested in this kind of quick feedback.
That particular aspect of the moderation system sounds good on paper, but was rather useless in practice.
Essentially, what "matters" is that people are upvoting or downvoting a particular post. Theoretically, it's good to have a bit of additional metadata telling us why they're doing it: i.e., do they find the post Funny, Insightful, or Informative?
In practicality, it's not that useful, or at least it wasn't put to any practical use by Slashdot when I stopped reading it back in the 2000's. At a moment's glance, it's pretty trivial to see why people might've upvoted a particular post - it's clearly meant to be funny, or it has a lot of informative links, etc. So the metadata of "why" was just redundant.
On the other hand, I suppose the metadata could have been put to some practical use after all. For example, it would have been perhaps useful to filter out all of the "Funny" [1] and "Insightful" [2] replies on Slashdot and to focus on the most "Informative" [3] ones. I don't remember the interface allowing you to do that. Perhaps they added it later, or perhaps it's something you might explore in your own system.
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[1] I mean, one can only read so many "Imagine a Beowulf cluster of THOSE!" jokes before one wants to jump off of a bridge.
[2] In my experience, 99% of the "Insightful" comments were just those that forcefully/eloquently regurgitated FOSS talking points that resonated well with established Slashdot groupthink. "Insightful" upvotes tended to mean "I agree with the author of this comment" and not "wow, actual new insights are presented here." Perhaps this might have been avoided if there was a separate "I agree with this" upvote method, distinct from "Insightful."
[3] It was easy to farm for karma this way; if you stumbled upon a recent Slashdot article without many replies, you could throw a few easily-Googled relevant links into a reply and be assured of getting a bunch of "Informative" votes. Nonetheless, while imperfect, the replies deemed "Informative" had a decent signal-to-noise ratio relative to the rest of the replies.