We have incentive to ask questions: getting answers and getting points for a good question.
We have incentive for answering questions. Points, badges, reputation.
But I see two problems with the voting system.
- The first is that there is little incentive to upvote. The consequence is clear on Stack Overflow. Plenty of good answers with a score of 0. Isn't it just as important to find these, and upvote them as it is to post and answer questions? Why no reward then?
- The second is that there is no scale, or metric, for how many upvotes an answer should get. If an answer has been upvoted 40 times, and another upvoted 4 times, what does that mean? (Assuming they are are both correct.) Is the first answer 10 times longer? 1/10th the code? Did it take 10 times the experience to answer? Is it in a language with 1/10th the userbase as the second?
Because we have no incentive to upvote, and no direction as to how much we should upvote, all rankings are somewhat meaningless.
A music website like thesixtyone.com solves this problem with the following solution:
- There are no downvotes.
- Upvoting (initially) costs you reputation.
- As more people upvote the same answers you've upvoted, you earn back that reputation, and then earn more reputation on top of that.
That way you have incentive to find things with low scores that should have higher scores, and upvote. You are rewarded for voting when your vote agrees with others, and penalized when it doesn't.
I'm not saying that this is the correct solution to Stack Overflow. But I am saying it's a step in the right direction.
There are currently 48,048 questions on SO with no upvoted answers.