I'd argue that there is exactly one "correct" view of comments on a document, per-community. The correct view is the one that best represents the range of opini

I'd argue that there is exactly one "correct" view of comments on a document, per-community. The correct view is the one that best represents the range of opinions of the community, and bests represents that community's cultural norms. To be specific, if I'm reading the comments section on Hacker News, I don't want to see comments only from people who agree with me or think how I do, and I don't only want to see comments from people I disagree with. I want to see what the community of HN readers thinks, in the particular way they express it. Additionally, I want to know that what I'm seeing is also what they're seeing. In a sense, this is still social filtering, except averaged over all members of a community, and with the same results for all members. The community responds to posts with approval or disapproval, through votes or comment responses, and this gets averaged (messily) by the moderators. I think, really, that there's an almost objective set of metrics for what makes a good comment thread. * The thread covers most of the held opinions & responses, with few to no 'duplicate' comments * The posts are well-written and polite * Assertions about the world are based on agreed-on facts, and justifiable (even if not agreed-on) conclusions stemming from those. * The posts respect any other cultural norms particular to that community. These sound subjective, but I think that neutral bystanders would tend to score a post similarly on these different metrics - i.e., there's actually a measurable quality of a post being 'polite', or 'reasonably argued', and it's not entirely relative to an individual reader (or even a single community!) On a polarizing political post, I don't want to read poorly written insults from the opposing position, but I also want to know that the other side won't be reading poorly written insults that misrepresent my side. I'd rather the best, most rational, and most empathetic posts from both sides be displayed as representative of the discussion.