I’m not a huge fan of karma-accumulation websites. You know what kind of site I mean: Other people can vote up or down your stories and comments, and you get points when you’re voted up, and lose points when you’re voted down. There are lots of these, each with their own scoring foibles: Digg and Reddit are two of the most well-known. Slashdot has done it for a while (in fact, I think they’re why I still call this concept “karma”). The concept is good: You limit the requirements for moderators by allowing users to essentially moderate each other. If a post or comment gets enough down votes, it might vanish. If a post gets a lot of up votes, it becomes more prominent. Fewer dedicated moderators generally means lower overhead costs and, in theory, a “fairer” moderation policy.

In practice, though, there are a lot of things to not like about these schemes. Accumulating points becomes an end in itself, which leads to posting a lot of simple or purposely-misrepresented posts (“whoring”). When points are used to control if your posts are seen at all, creating multiple sockpuppet accounts to vote up your own contributions (“gaming”) is inevitable. On the larger sites, an above-the-fold link can mean tens of thousands of hits; gaming then becomes a lucrative business. Preventing whoring and gaming through algorithms can work, but search engine optimizers are smart and tenacious. It’s a continuous arms-race.

Stack Overflow is a point (“reputation”) accumulating site that somehow works extremely well. At first glance, it is a simple programming question-and-answer forum where you gain reputation for answering questions and having those answers voted up or chosen as “correct” by the asker. But there’s a number of things I haven’t seen anywhere else that makes Stack Overflow excel where other sites struggle. The most obvious difference is that you are able to do more things as you gain reputation. You can’t even vote up questions or answers until you’ve received a couple of votes of your own, increasing the burden to entry for sockpuppets and gaming. Maybe more importantly, points accumulation isn’t single dimensional. Stack Overflow gives you badges for activities that are difficult to game, and displays your badge count right next to your reputation.

But there’s a bigger reason why this works on Stack Overflow. There’s no real benefit to gaming or whoring. Since the focus of the website is question-and-answer, instead of directing traffic to other websites, there’s almost no way to make a profit from having a question voted way up. And the relative smallness of the audience compared to some of the giants out there means that even if there was a way to turn a profit, focusing on other sites would still give you a better return. What’s left to be seen is if Stack Overflow can keep such a high signal-to-noise ratio as it continues to grow.