I think you can get to know somebody by asking questions which have a wide variety of answers and then comparing the answers across a pool of applicants. Microsoft does this. A friend of mine reported that one of the questions was “How would you design an oven so that it was completely safe?”
He asked for clarification on completely safe, first of all. Then they said “An oven that a small child or an elderly person living alone could use without posing a danger to themselves or to their home.”
The genius behind this question is that you can take an administrative approach, an engineering approach, a construction approach, a policy approach, and even a legal approach. It’s completely open-ended. But by seeing how the people choose to think about the problem you can infer whether they are suitable for the job you are hiring them for.
When I interviewed people to work for my house cleaning startup, I put a ¾” empty square on the application and asked them to fill it in. All they had was a blue pen. The more completely they filled in the box, the more attention I thought they paid to detail. some people just scratched across the box very lightly.
As a final example, I was on a hiring committee for an IT position. We broke a computer (in multiple ways) and had the interviewees fix the problems in front of us. This told us not only if they knew something simple about computers but also revealed their problem-solving style in a pressure situation. This was important because we would ask the technicians to fix computers in front of classes and faculty during classes if they went down suddenly. They needed to be able to think clearly while we were talking to them.
So for engineering it gets tougher. But I think a little forethought can bring some interesting details to light. Maybe a guideline is: Don’t expect the question/test to tell you who will be really good, but do design it to tell you who will be really bad.
But there is a lot of self-delusion going on when you try to use tricks like these. Still…even if they gain you no real information, they are fun to do. :)
And never ask anybody what their plan is in 5 years. In my experience, nobody does what they said they were going to do…so don’t cloud your decision-making process with information you already know is probably falsified.