So, a further thought about Paul Graham’s Hacker News and its comments policy. (See yesterday’s post for details.) If reddit allows you to approve or disapprove of things you haven't even read, Hacker News appears not to allow you to disapprove of things at all: you can click the “up” arrow or . . . well, do nothing at all. Or so it appears. Because it turns out that when your karma points reach a certain threshold — apparently 100 — you suddenly acquire the opportunity to downvote a post/link. Interesting! It’s only when you have contributed value to the community that you are entrusted with the power of negativity.Something similar is being done at another hacker site, Stack Overflow, where upvotes add 10 karma or “reputation” points to a post’s author, while downvotes remove two reputation points from the post’s author — and one from the reputation of the person doing the downvoting. This too is interesting! Here you have to ask yourself before voting something down whether you feel strongly enough about it to take a chunk out of your own reputation to register your disapproval. Kinda like real life.These are great examples of “choice architecture,” but not quite of the “nudge” variety. They are more than nudging you to make certain kinds of decisions, though. Hacker News is allowing you to purchase power with good behavior, while Stack Overflow is subtly threatening people who consistently misbehave with expulsion from the community. I like these models very much, but at the moment I can't see how they could be applied to sites where there are just comments rather than votes on the value of posts. Regular old blogs — as ace commenter Tony Comstock remarks in relation to my previous post — may have to depend on the blogger’s own ability to model civil discourse and to gently manage comment threads. But I have seen many, many peaceable and thoughtful bloggers get overwhelmed by trolls and other hostile figures. So there is, I think, a desperate need to develop a choice architecture that works for the garden variety blog and its comment threads.