One particular line of questioning that I found most useful, and research suggests is very revealing as to what motivates and drives an individual to eventual success, is as follows:

When you were young, who was the person that was most influential in teaching you valuable lessons about life? What were those lessons the person taught you? What are those tapes this person put into your head that are still there today and have emerged as guiding principles for you?

Usually the person is a parent, an influential teacher, or some other authority figure. Often times, this person came into the individuals life as early as grade school or high school.

The lessons you are looking for are basic principles that suggest a high degree of self confidence, a sense of personal responsibility, a strong drive to achieve, and solid fundamental ethics. No hint of these kinds of traits should be a red flag.

The interviewer should then probe in depth the role the interviewee played in outside activities or other initiatives to see if the existence or lack of these kinds of traits, matches up with the individual’s track record in achievements.

While it is important to know the technical experience and capabilities of every applicant, equally important (probably more important) is to gauge his or her fundamental qualities as a person. One way to measure that is by using the line of questioning above. Basing on the answers you'll receive, you will get a sense of a person's history, his or her values, dependability and aspirations.

Sure, the applicant could make up stories but that is why you are interviewing the applicant anyway - validate whatever's on the resume and the answers to other interview questions. A thorough background investigation is also useful.

Even when I'm not hiring I actually interview applicants at least once every week as I am always in the lookout for fresh talent. One thing that I have learned is that even though you are only entertaining an applicant for a entry-level post, knowing what the applicant is built of is still very important. You hire the wrong person, even if it's just for a staff position, it could cost you a lot.