Shorter version: downvotes are more likely to be thoughtless.
This is why democracy + free speech (in theory, at least) works. No matter how unpopular, a voice cannot be silenced. If you don't like a person's viewpoints, you can't shut them down by downvoting them; you can only upvote the viewpoint you do like, and / or present your own position yourself, if no one else has done it.
For example, in my Facebook application Wildfire stories are up voted only if you pass then on to your friends. As you mentioned to me yesterday, delicious/popular is interesting because it's based on pages people bookmarked for themselves.
John.
Comments are useful, but that slants towards controversial topics.
Personally I miss having the option of a downvote. Yes I agree downvotes can be an uninformed reflex, but removing any voice of disagreement seems overly harsh.
I'd say have upvotes that count as 10 points, and downvotes that count as 1 point or something like that.
Do other people find the same thing?
The trouble is that the meanings of up and downvotes are different for news stories and comments respectively. For a comment, the votes almost exclusively mean agreement/disagreement. Only in rare cases do I disagree with a comment but still find it so important that I vote it up. This is different from, say, a scientific paper where this happens frequently.
Overall I think downvotes are unnecessary and cause a lot of bad blood.
Downvotes mean: "I find this especially uninteresting"
Good article that agree with the user = comment/up vote
Bad article that agree with the user = ignore
Good article that disagree with user = comment/down vote
Bad article that disagree with the user = down vote
Unless everyone actually vote up/down purely base on how good the article is and not their opinion, removing the down vote button is not a bad idea...
The voting button is a good idea if it's a poll, but the "hotness" of something is probably better tracked by the comments and other actions a user take...
Also interesting news that was generating a good discussion could tend to persist and stay near the top. This would encourge thoughtful comments as you are not penalized for taking some time to think about the matter rather than hastily shooting from the hip.
Secondly, it'd be hard to extract a quality measure from comments alone - there are a number of metrics (number of unique users commenting, rate of commenting, amount of voting...) but how do you get from that to a quality measure? How do you distinguish controversy from quality? Or comment threads full or jokes and snark?
Also, commenting on anything you disagree with or dislike would result in that link getting a boost, which can't be right.
All that said, I think comments could be used, but modestly, as part of a bigger algorithm.
If you consider comments to be analogous to links, the quality of a news item (or comment) can be extracted as easily as pagerank determines the quality of a webpage. Controversy can not be distinguished from quality because they are orthoganol measures. Many controversial issues (to VC or not to VC) are of high interest to readers of this site and would be considered high quality while off topic political controversies would probably not be considered high quality for this site. In general, most interesting things are controversial.
The existence of noisy comment threads (jokes and snark) is a good point. I would think that some form of Bayesian spam filtering could penalize these comments. Off topic comments could be penalized similiarly if a Bayesian filter was trained using the text of the news item.
I disagree that disagreeing or disliking is disagreable. I would call it conversation.
I don't think a bigger algorithm is the answer. One with a good impedance match would suffice.
http://reddit.com/info/2r8d8/comments
vs.
http://programming.reddit.com/info/2qbye/comments
"Quality" sounds like a good metric until you realize that upvotes mean "I agree!", not "Good comment".
... although most other commenters didn't agree.
Summary: up only voting measures personal interest. It tends to promote anything that has a constituency. Up and down voting measures community approval. It tends to promote group-think.
