Following up on yesterday's post, I invite you to look at the logo to the right. Undoubtedly, it is one you have seen hundreds, if not thousands, of times. How many of you, however, have ever noticed the arrow between the "E" and "x." It is a wonderfulFedex-logo  example of negative space and I want you to think of it as a metaphor for training your mind to "see what isn't there."

Let me give you a more concrete example of "seeing what isn't there." Consider for a moment the story of Abraham Wald. As a young man during World War II, the Hungarian-born mathematician served as a statistician and undertook a study on behalf of the British Air Ministry. Among his responsibilities was to assess the vulnerability of Allied airplanes to enemy fire. The intent of those who commissioned the study was to devise methods to better protect the aircraft.
Therefore, as the airplanes returned from their sorties, they were diligently assessed for damage. It was soon apparent from all the existing data that certain parts of the plane—such as the tail—were being damaged disproportionally more than other parts of the plane.

Naturally, this led RAF officials to recommend that those areas of the plane be reinforced with extra armor. Wald, however, reached just the opposite conclusion. He argued that data was only being collected from the planes that had successfully completed their mission. It didn’t include those unlucky enough to be shot down in battle. Recognizing that this created a selection bias, Wald came to the counterintuitive conclusion that the parts of the returning planes that were not riddled with holes should be the areas that received additional fortification. Why? Because he understood that those areas of the aircraft that had been hit and yet still made it back were not critical to the mission’s success.

Wald was only able to do this by "seeing what wasn't there." He "saw" the aircraft that didn't return.