I have often wondered at the practice on SO, SF, and the other sites where someone will ask a question and an answer will come in that says 'Look here: http://link elsewhere". Rarely will the link have exactly the answer necessary--often it's an entire article--yet these answers get voted up.

Why is that, exactly? I realize this is subjective, but my own thoughts are that one should try and give the answer (even if the answer is 'no, it can't be done' or 'no, I don't think it can be done' -- very different answers) and then if you have a link that explains it, go ahead and post it within the answer.

What does the community think about this?