FAQ says "To gain reputation, post good questions and useful answers." Is it valid to downvote an answer because it isn't useful (e.g. doesn't give enough information to help?) Or downvote a question because it is missing information. Or is downvoting primarily for disagreeing with an answer?
What is the purpose of downvoting questions or answers?
I downvote for actually wrong information, which is the clearest case for down-voting.
I've also been known to do it for answers that lack a certain professional tone or are actively mocking the asker for asking what they did.
I don't downvote for missing information, that just means I can either answer that question with the missing information and probably gain more upvotes, or leave a comment with the additional information.
I downvote questions that are poorly written, while making allowances for the fact that English may not be the poster's primary language (which is usually pretty obvious). Some question can most generously be classed as idiotic, while others simply aren't a real question or are written in gibberish.
Rather than downvote questions that don't belong on the site, I prefer to vote to either close or move the question to a more appropriate site.
I normally downvote answers that I know to be technically incorrect, invalid or simply don't address the question that was asked. Less often I will downvote answers that are poorly worded or written in a style that is inappropriate for this site, such as those which are intended to insult or inflame, although the latter are generally flagged for moderator attention instead.
The reason for downvoting is to try and discourage poor questions and answers, just as upvoting is intended to improve the standard and reward those who do so.
When it comes to questions, I downvote ones that the asker doesn't have appear to have put a lot of thought in to asking them or into working things out for themselves. Also where it's like pulling teeth to get the asker to contribute towards finding their solution... oh yes and I tend to dislike "Do my homework for me" questions.
in my mind:
"X doesn't work. What do I do?"
is a bad question worthy of a downvote, and
"X doesn't work on mac osx server 10.5.8 with all current patches applied. I installed it without any errors, but now it won't start correctly. I get the following error in the logs... etc"
is a good question.
You want good answers to "rise" to the top. Answers that are off topic, wrong, possibly destructive, misleading, etc. should be downvoted to bury it, or at least alert the questioner that there's a problem with it.
Questions usually get downvoted because they're inappropriate, vague, horribly worded, etc. and usually end up getting closed or migrated if they're off topic.
The system is supposed to help encourage the community standard for asking and answering questions.
After letting my brain mull this over for a bit, I think I've only downvoted a question when the person responds rudely to comments & suggestions intended to help them improve their question.
