I would be very interested to hear you guys talk a bit more about your technical interviews. What makes for a good technical interview and what approaches do you take?

Sometimes, these can be a "stump the chump" session and I think that can be counter-productive. That is, you might have a real SQL Server wizard who is weak in one area (maybe like Temp Tables vs Table Variables) and so just trying to stump an interviewee is not necessarily a good measure of overall skill.

How do you approach assessing someone's technical expertise? Do you focus specifically on just SQL Server, or SQL Server as it applies to your specific business? Do you use formalized questions - or find a discussion more useful?

What in your view, is a good guide to an effective "technical interview"?