There's been some interesting comments on my entry: "The Inside Scoop on Interviewing at Microsoft", and I just wanted to follow up and expand on a couple of points.
Hiring new staff is an incredibly resource intensive project. There's a reason why most senior managers at Microsoft list hiring as one of their top four or five objectives for each year. It's not just an interview: there's work to define a role, "evangelism" to ensure that that open position gets seen by as many talented people with relevant skills as possible, winnowing out resumes to find potential candidates, conducting potentially tens of telephone interviews for each job, organizing a day of interviews for each shortlist candidate, actually interviewing, following up on peer interviews, writing up the interview, following through to an offer or a decline - it all takes an immense amount of effort. The old cliche of "marry in haste, repent at leisure" works almost as well for a job as for a romantic partnership.
I accept the potential criticism that just because someone doesn't answer a question in the expected manner doesn't make them wrong. A good interviewer should definitely be open to evaluate their question and drill deeper or try a different tack if they feel like the interviewee is misunderstanding the question, or indeed being open-minded enough to evaluate their answer on its own merits. A bad interviewer makes their decision in the first few minutes based on how much they click as an individual with the interviewee. I try to reserve judgement on the final hire / no hire decision until the very end of the interview and instead work on identifying potential hire and no hire characteristics that I can verify with further questioning.
Interviewing is one aspect of working at Microsoft that I really love - I think the process that we've adopted is pretty good. Probably the biggest challenge for most Microsoft interviewers is that it's something of an art rather than a science: there's no magic, repeatable formula for a perfect interview. The right question to ask at any given time depends on the personality, the experience, the skills, the seniority and the fit to job of the person being interviewed, yet you can't know the answers to all those things before you interview the candidate (otherwise the interview itself wouldn't be needed!) Any interview is therefore an iterative loop of understanding someone more and therefore being able to ask more targeted questions that reveal more of the true character and abilities of the interviewee.
If you interview and don't get accepted, don't automatically assume it's because you're not of high enough caliber to work at Microsoft. It's quite possible that you just aren't the right fit for the job at hand. I'd expect that if I interviewed for a random 100 jobs at Microsoft, I might get an instant "no hire" for 80 of those jobs, a possible hire (but with no real hope of being a stellar performer) for 15 of those jobs, and find 5 or fewer jobs where I could really make a difference and stand out. Actually, it might be even more dramatic than that. The hidden secret that I wish more job/career books would cover is actually finding the right five jobs in the first place, and then of course to make sure that you communicate well enough that those who interview can see your strengths there.