The submitted article is interesting, and it is especially reader-friendly that the author first shows a simple karma model in both mathematical notation and pseudocode, and then shows a more refined karma model each way. I think I agree with buff-a's comment from 12 hours ago and the several participants replying to buff-a (the top comment in this thread as I write this comment) that the best behavior to reward is a commenter waiting until the commenter has something thoughtful to say.

The other issue that has come up in multiple comments already posted is the role of downvoting. Downvoting is a pet issue on HN--I have seen more than a dozen full threads about downvoting and scores of comments about downvoting in other threads in my 1010 days of registered participation on HN. Before I came on board, 1284 days ago, pg (the site founder) wrote, "I think it's ok to use the up and down arrows to express agreement. Obviously the uparrows aren't only for applauding politeness, so it seems reasonable that the downarrows aren't only for booing rudeness."

http://news.ycombinator.com/item?id=117171

Although I would agree with putting in a two-dimensional voting/flagging system (with one dimension being agreement with the statement(s) in the post, and the other dimension being a judgment of how much the post contributes to the community), while such a bivariate system is not yet implemented, it makes sense to downvote comments without further follow-up comment if they add nothing to the posted discussion as it is already posted, in light of the submitted article or question opening the thread. No one should be obligated to comment on a useless post before downvoting it. It is the responsibility of each commenter (as several commenters here implicitly agree) to make the case for his or her own comment being visible by what is said that is new and helpful in the comment.

When pg opened a thread 142 days ago with the question "Ask HN: How to stave off decline of HN?"

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

he wrote, "The problem has several components: comments that are (a) mean and/or (b) dumb that (c) get massively upvoted."

That's still the key issue. It doesn't do any reader of HN any good if a comment that is dumb gets net upvotes. Nor does it do any good if a mean comment is upvoted--that causes active harm to the community. If participant behavior brings about higher scores for good comments, and lower scores for mean, dumb, or other bad comments, that is helpful to all readers of HN.

Some users who are worried about downvotes are worried also about HN hivemind or groupthink. It may be that there are unexamined opinions without factual warrant that are held by the majority of HN participants--that is to be expected on the basis of psychological research.

http://www.project-syndicate.org/commentary/stanovich1/Engli...

The thing to do about groupthink is to dare to comment, karma be damned, and to respond with thoughtful, informative comments that challenge majority opinions. I have also thought that it might be useful for veteran participants here on HN who have a Web presence to post a Web page or blog post discussing what they see as the main hivemind or groupthink issues on HN, with citations to good sources of information on those issues, and then to put links to such online discussions in their user profiles. That way, if a user is a contrarian on an issue that a lot of HN participants care about, the user can invite all other HN participants to look up facts on the issue. That might help raise the level of discourse here.

After being here 1010 days and seeing a few rule changes and MANY discussions of upvoting, downvoting, and karma rules, I think the main thing to do here to improve the quality of discussion is to UPVOTE more. Upvote a person who asks a follow-up question like, "Do you have any sources to back up that statement?" (I often see such comments grayed out, indicating that they have been downvoted, but comments that ask for more verifiable information are nearly always helpful.) Upvote a person who says "Thank you" out loud, and silently upvote a comment that you think deserves thanks for politeness or thoughtfulness. Upvote a comment that provides a link to an online resource you didn't know about before. Upvote a comment that apologizes for a gaffe or that admits a factual mistake. Upvote that which is good, and there will be fewer problems with inaccurate signaling here.

Feel free to review the site guidelines

http://ycombinator.com/newsguidelines.html

and the site welcome message

http://ycombinator.com/newswelcome.html

for guidance on what is desired here and thus guidance on how to vote.