There's an interesting discussion going on over at Evil HR Lady about whether it's okay to ask for feedback when you don't get a job, with a lot of people pointing out in the comments section that when they've agreed to give rejected candidates feedback, it inevitably ends with the candidate trying to convince them that the feedback is wrong and they should get the job. (I think it's great when candidates ask for feedback, but that's precisely the reason I'll only give it via email and not over the phone; I don't want to get trapped in that conversation.)
Anyway, it made me think about how often candidates are convinced that they are precisely right for the job and they become baffled when they don't get an offer. Sometimes they even become aggressive and hostile, but that's another post.
There are all kinds of reasons for why you might not be chosen for the job, no matter how qualified you think you are, including:
1. Your qualifications aren't as strong as you think they are. Your assessment of your skills isn't in line with the reality of the situation.
2. Your qualifications are very strong, but someone else's are stronger. (It's odd how often candidates shocked that they didn't get the job overlook this possibility, which is one of the most common.)
3. You don't have an accurate understanding of what the job is all about, and therefore your opinion of how well-matched you are is based on an erroneous foundation. This one is surprisingly common. For instance, I did a phone interview with a guy today who really did have an impressive business background and kept referencing examples from it -- but the job he's applying for wouldn't make much use of those skills. He picked out a couple of smaller aspects of the job description and focused on those, missing the larger picture (which is that the job is way more clerical than he realized).
4. You're well qualified, but you have some other characteristic that would cause you big problems here, such as an inability to listen without interrupting, or trouble answering questions clearly, or a hostility problem. I'm not going to knowingly put someone in a job that they're likely to run into problems in -- both for the manager's sake and the candidate's sake.
So don't become shocked and irate if you don't get a job you thought you were perfect for. After all, chances are good that the hiring manager knows better than you do about who will thrive in the position. That is a good thing, because you do not want a job that you will not excel in.
People do make hiring mistakes, of course, but in general, it makes sense to respect the opinion of the people who work there, who know the needs of the job intimately, and who know better than you whether or not you're likely to be a good fit for this particular position with this particular boss in this particular culture in this particular company.
None of which is to say that you shouldn't ask for feedback. Just be sure you're asking out of a sincere desire to know, not to try to argue your case.