I generally find that asking specific questions about a technology or technique is not really valuable. My preferred method of interviewing is to sit down and

I generally find that asking specific questions about a technology or technique is not really valuable. My preferred method of interviewing is to sit down and talk with the candidate about "stuff", which should include said technologies/techniques. After a fashion you will get a good understanding of what they know about the subject; where they are strong and where they are just blowing smoke. You'll also know more about how they would integrate into your team. So just relax and talk to the candidate and don't worry about asking the magic questions that will answer all your prayers. :)