Thanks to everyone for their interesting comments. Some of the forms of site behavior mentioned here I don't think I have ever observed. I don't read the code for the site software, so I just use the site empirically. The discussion of trade-offs involved in different kinds of site voting behavior defaults has been very helpful to me.

My overall perspective on any online forum's forum rules is that I just deal with them. I don't take any set of rules personally. I don't assume any kind of enforcement action or limitation on my own forum participation is directed at me as an individual, but rather is a forum management response to forum issues. If I enjoy a forum, I keep right on participating. If I don't enjoy a forum, I take my participation elsewhere without feeling offended. I happen to like HN a lot. To each their own.

As to specific observations of voting behavior, to the best of my knowledge and belief, when I upvote a comment or submission, and when I downvote a comment, my votes immediately change the score of the item I have just voted on. I try in my own mind to upvote more often than downvote, but I have no way to keep track of my actual count of votes up or down. I do like to clean up the comments, so I definitely downvote from time to time, and sometimes in bursts of downvotes in one thread. Unless I am wholly mistaken in my observation, my votes count as ups or downs on those items, in real time. It has been my observation that my own personal karma score will sometimes be stable for hours at a time, even if I have made new comments or submitted new articles, and it may be (I don't know) that I am running into some automated response of the site software such that my karma score is frozen if I have just been downvoting repeatedly. But it often seems that overnight, or after a while, my personal karma score becomes unstuck, and anyway I don't worry about this too much. I look at my threads view from time to time both to see if anyone has replied to any of my comments and to see what the aggregate votes are on those comments. If I am below 1 in aggregate score on some comment I have made, I try to think why readers would decide to downvote it. If I see someone else get a conspicuously high net score on a comment in a thread where I have also commented, I try to figure out what he or she did right to achieve commendation from other participants. As long as the site in general is worth reading and interesting to me, I don't especially worry about how its voting behavior is implemented. It's fun for me to learn from other participants here what kind of rules are visible in the source code and what kind of incentives may be designed by management to keep the conversation worthwhile. Since 1992, I have been a moderator on one or another of a variety of online forums, and I'm always deeply curious about what makes online communities successful and valuable to participants. I think HN is doing a good job.

P.S. I like many of RiderOfGiraffes's submissions and comments, and have certainly upvoted more than a few (and perhaps downvoted none of them). I too recall some thread in which pg mentioned RiderOfGiraffes favorably, although I don't have the link at hand. I would regret seeing RiderOfGiraffes leaving the site or changing his username, because I like to see familiar usernames as a clue that a comment or submission will be worth a read.