Well, there are two different aspects in Less Wrong system : the global karma of a person, and the score of a comment.
I agree that the “global karma of a person” is of mitigated use. It does sometimes give me a little kick to be more careful in writing on LW (and I’m probably not the only one), but only slightly, and it does have significant drawbacks.
But the score of one comment has a different purpose : the purpose is that a third party (not the one who posted the comment nor the one who put the upvote/downvote) can easily select comments worth to read and those which are not. In that regard, it works relatively well—not perfectly, but better than nothing. And in that regard, it doesn’t really matter if the OP understands why he is downvoted, and in that regard, explaining why you downvote does more harm than good—it decreases the signal/noise ratio (unless the explanation itself is very interesting, like it points to a fallacy that is not commonly recognized).
Well, there are two different aspects in Less Wrong system : the global karma of a person, and the score of a comment.
I agree that the “global karma of a person” is of mitigated use. It does sometimes give me a little kick to be more careful in writing on LW (and I’m probably not the only one), but only slightly, and it does have significant drawbacks.
But the score of one comment has a different purpose : the purpose is that a third party (not the one who posted the comment nor the one who put the upvote/downvote) can easily select comments worth to read and those which are not. In that regard, it works relatively well—not perfectly, but better than nothing. And in that regard, it doesn’t really matter if the OP understands why he is downvoted, and in that regard, explaining why you downvote does more harm than good—it decreases the signal/noise ratio (unless the explanation itself is very interesting, like it points to a fallacy that is not commonly recognized).