This one is particularly good if you’re hiring for a communications role, a client success role, or a programming/developer role. It’s a challenging question so you get to see how the candidate thinks under a bit of pressure. You also get to see how adept she is at thinking through complexity and communicating effectively. Finally, the way the question is structured also allows you to learn something about the candidates judgement. You’re not asking her to tell you about the most complicated thing she’s ever come across in her life, you’re asking her to choose the most complicated thing that she could get you to understand. Does she choose something impressive but ambitious when it comes to teaching you about it? Or does she go with something simpler that she’s sure she can get you to wrap your head around?

Source: I don’t remember but I didn’t make this one up. It came from somewhere…

Have you asked this question? How did it go? Do you have advice for how best to ask it? PLEASE RATE! AND WRITE A REVIEW (in the comment box below)!