- Upvotes need to be weighed by karma, and karma of exemplary members of the community needs to be seeded by you (and other exemplary members). This way cliques of mean/non-insightful users can upvote each other to their heart's content without making any appreciable difference in their karma value.
- The above would fix the quality of articles on the front page, not just the quality of comments. Our most successful blog post to date was "will the real programmers please stand up" (http://www.rethinkdb.com/blog/2010/06/will-the-real-programm...) which is at best a provocative rant. The actual technically insightful content isn't nearly as successful. TechCrunch mastered the art of linkbait headlines. Weighed upvotes will solve this problem.
- Anonymity breeds animosity. If I don't know someone it's much easier for me to say mean, dumb things (see: YouTube). The solution is somewhat controversial, but I strongly believe the downsides of threaded discussions strongly outweigh the upsides (ability to carry on multiple discussions at a time). Removing the ability to have threads will force people to pay attention to who they're talking to and have a coherent discussions instead of snarky oneliners.
- Moderators need to be able to lock down threads that are getting out of control.
- When the article is off the front page, the discussion quickly dies off with it. There needs to be a "hot discussions" tab that allows people to continue the conversations. This encourages people to get to know each other and participate in a coherent discussion that spans beyond 24 hours.
The decay constant should also be decreased, so that interesting submissions stay longer on the homepage. I usually don't comment on old submissions, because it feels like no one reads or votes on them.
I am willing to sacrifice the number of good articles on the homepage each day for the quality of comments on each article.
(edit: added last paragraph)
Also, having the stories leave the front page so quickly encourages people who are just interested in getting points to throw out whatever garbage they can in hopes of grabbing a few upvotes by being one of only a few comments on a given submission.
I really agree with your last two points. I don't think there are any examples of a large community effectively self-moderating; you need someone willing to ruthlessly delete the crap.
I'm thinking about it, and I can't really see any advantage of the Reddit-style format over a traditional forum if you're trying to build a thoughtful community. In online terms, there's only been one non-forum where I've really felt part of the community, and that's a slow-moving blog with a smallish group of great regulars.
Sooo, use facebook for auth? :)
I think HN is an ideal place for personally identifiable comments, we're all professionals here right?