HN's algorithm for ranking submissions is as effective of any I've seen for UGC websites, but comment ranking seems very heavily weighted to first submitted.<p>Perhaps HN does this already and time is just less of a factor than for submissions?
<i>comment ranking seems very heavily weighted to first submitted</i><p>Comment rating used to be much weighted to first submitted, implicitly, because later submitted comments almost never got enough karma to move into visibility. Something was done to the comment karma algorithm in the last year or two to make recency LESS weighted than before, and I think it has improved the quality of comments in many threads.