I believe that a large factor in how it works has to do with the average karma score of the voters. (Visible on your profile page). From what I have been able to determine the higher your average score the more weight your votes have, and the longer it takes for your comments and/or submissions to fall down the page.
This seems to be designed to reward people who make consistently good submissions and comments, although it also has the bad effect on making it quite penalizing to make a comment that goes against the groupthink.
I think that other factors that may have an impact are age of your HN account, and your total karma count. So long story short votes by older accounts that make quality submissions and comments are worth more.
It makes it quite rewarding to quickly post conformist opinions in typical circle jerk threads, at the same time it punishes participating in smaller and older threads.
Yeah, I really hate this. I have some relatively unpopular opinions (e.g. I believe that porn, strip clubs, and prostitution are the core problem holding back equality of women) but trying to express these opinion penalises me. The downvotes eventually hide my opinion.
I don't know if there is a better model for human discourse on the internet. Maybe it's a good thing that unpopular opinions get silenced, unless they're phrased in very careful, smart-sounding ways. I have to go through great lengths to convince my voters that I'm not a complete idiot for believing some things, and it's a lot of work. It's just easier to express unpopular opinions very selectively.
edit: Wow, there's a very good-looking response to this by lostcoyote which is marked as dead and will probably disappear. What a weird coincidence, very à propos.
> I believe that porn, strip clubs, and prostitution are the core problem holding back equality of women) but trying to express these opinion penalizes me
It's particularly bad because of the dominance of males on this site, who unsurprisingly are on the whole far less sensitive to the issues of equality of women. How HN tends to respond to women's treatment in tech is a good example of this. HN is far more apt to attack Apple than attack misogyny[1][2].
Recently I've made some posts questioning the morality of advertising[3]. But, as Upton Sinclair said so well, "It's difficult to get a man to understand something when his salary depends on him not understanding it." My comments were quickly down-voted.
I expect this comment itself to get down-voted quite a bit.
Hopefully they account for controversial comments, too. If a comment gets 130 upvotes and 145 (karma-equivalent) downvotes, I want to see it. Also, I know that dang has mentioned helping minority opinions out more than once.
This seems to be designed to reward people who make consistently good submissions and comments, although it also has the bad effect on making it quite penalizing to make a comment that goes against the groupthink.
I think that other factors that may have an impact are age of your HN account, and your total karma count. So long story short votes by older accounts that make quality submissions and comments are worth more.