I think it is important for questions to be within the scope of the resume. If the applicant claims 20 years of Java only experience, throwing in a few of thos

I think it is important for questions to be within the scope of the resume. If the applicant claims 20 years of Java only experience, throwing in a few of those questions is just a sanity check for that claim, especially if that claim is one of the reasons you are hiring them. A sportswriter who claimed an expertise in basketball wouldn't feel it unfair to be asked a few trivia questions in an interview. If he didn't know how may winning seasons the Chicago Bulls had with Michael Jordan then maybe he isn't as expert in basketball as he claims. Where these questions are unfair is when the applicant is more of a generalist. They have worked on very diverse projects in multiple paradigms and multiple languages. Their skill lies not in knowing how to use their tools, but in approaching new tools and quickly understanding how to use them. If you are a Java shop and someone comes into the interview with little Java experience then asking questions about Java specific type enforcement is going to leave them a little flustered. Cater the interview to the applicant, not necessarily to the position. Then evaluate your understanding of the applicant with respect to the position and see how well they fit.