http://news.ycombinator.com/leaders

here on Hacker News from time to time is that pg's last major change in the site code (to make comment karma scores invisible to persons other than the person posting the comment) really seems to have made a positive difference in the site. That change was quite controversial when it was made.

Site founder pg began the experiment by opening a thread, "Ask HN: How to stave off decline of HN?"

http://news.ycombinator.com/item?id=2403696

After looking at the discussion there, he announced an experiment

http://news.ycombinator.com/item?id=2434333

601 days ago of not publicly showing comment karma scores, but rather just letting each user see her or his own comment karma scores when logged in. That change was protested in several LONG threads in the first few months after the change, but what I noticed is that I started seeing the comments of the users from whom I learned the most, the most often, more consistently sorting to the top of threads, and on the leader board I noticed that the AVERAGE comment scores (still disclosed there) of the 100 highest-karma users began better matching who was making substantive, helpful comments as contrasted with who was making comments that were, in pg's words, "a) mean and/or (b) dumb that (c) get massively upvoted."

A reality check on what kind of comments get upvoted is to look from time to time at the bestcomments list,

http://news.ycombinator.com/bestcomments

which is still not exactly really a "best of" list of HN comments, but which has converged to better quality since that software change. The user jgrahamc appears to have seen his average comment karma score rise under the new software settings, deservedly so. Other users whose comments are especially thoughtful, whose user profile pages I visit to look up their most recent comments, also appear to have gained in average karma over the last year and a half that that software change has been in effect.