Harvey Mackay wrote a great book in 1995 called Swim With the Sharks. In it he tells a story about going to a convention of envelope makers (hard for me to imagine too, but he was in that business) where a veteran of the envelope biz asked him: "what do you get for your scrap?". That is with the "s". Turns out that the difference between making it or not making in the envelope business is how much you get for those little scraps of paper that don’t make it into a finished envelope. I gather the envelope business is pretty price competitive!
I bring up this story because in many situations there is one question that can tell the whole story. There is one question that illuminates layers upon layers of information about a person, a project, or a business.
That old guy at the convention of envelope makers learned all he needed to know about Harvey Mackay’s envelope business when he asked that one question. From the answer he would discover if Harvey knew what he was talking about, if Harvey’s business was running well, and if Harvey might know something useful.
Every business and many situations have a “one question” like this.
If you hire a lot of people, you probably have your favorite interview question. Sure you ask 20 questions, but there is probably one that tells the whole story. For me it is: “Tell me about the worst place you ever worked.” Our company culture is very important to me and I want to know how someone is going to contribute positively to our culture. The answer to this one question tells me if the person will take ownership of their positive contribution to our company culture. If you are hiring for a technical position, you might ask a question specific to the technology – something like “How do you get around the memory allocation problem in ___?”. You can see here that I don't hire the technical people but you get the idea. The answer to one properly asked question tells you the whole story.
Great salespeople employ this one question methodology all of the time. Our clients are marketing people and asking them: “What is the performance metric you are most worried about achieving next quarter?” tells a lot. From the answer we find out if they are inclined to measure things, if they have one problem or many, and what they are going to be thinking about when staring at the ceiling at 3 AM. Armed with that information we know if we can help them or not. All in One Question.