We've had many discussions here about the hiring process, with great contributions from those who do the interviewing/hiring and those who have been through the process. Here's an interesting article that suggests that most organizations are doing it wrong.
Why interviews are a lousy way to judge candidates
I must say though that while the writer has pinpointed a problem, I'm not big on his solution of trying to make the process more measurable.... managers are consistently overconfident in their ability to identify the best candidates using a job interview. We cling to the fanciful notion that we can perfectly predict future job performance, despite overwhelming evidence against it. We all want to believe that we are good judges of character, yet we do not bother to collect the evidence we would need to test that belief. Rather, we rely on gut intuitions about whom to hire.