text: Behavioural based questions are a good indicator of their relevant experience, as it focuses on actual situations versus academic theoretical situations.  For example, you could ask a question like "Tell me about a time when you did something extra to improve a patron's experience."  or "Tell me about a time when you did more that was required of you."  Those who can't answer these well suggests to you that they don't have the experience or understanding to do the job well.  With such questions, you'll find the people with the right attitude as well as the people who actually know about what you are asking.