A Lesson in Seeing What is Not There

During the Second World War, the U.S. military ran a classified program that involved bringing together some of the best mathematical minds in the country to help with the war effort by masterminding the best solutions to important problems.

One of the problems the group was tasked with was where to put the armor on aircraft. (This story comes from the book “How Not to Be Wrong” by Jordan Ellenberg.) The issue was that armor is heavy, so using too much makes planes less fuel efficient and less maneuverable.

The military compiled some data and presented it to the math whizzes. They did an inventory of where the bullet holes were in the planes that came back from combat missions. The numbers showed that most of the hits were in the main body of the plane. There were fewer hits in the fuel system, and the engine compartments had the fewest bullet holes of all. The military analysts took this to mean that they should focus on reinforcing the main fuselage with armor, since that’s where most of the damage was being sustained.

The mathematicians then pointed out the flaw in that thinking. The military analysts were only looking at planes that came back. They weren’t seeing many bullet strikes to the engine compartments for the simple reason that planes that took hits to the engine were more likely to be at the bottom of the ocean, or smoldering wrecks on the ground. If anything, the large number of bullet holes in the body of the returning planes proved that is where the planes were least vulnerable. The advice from the math scientists seemed counterintuitive at first but was utterly logical: put the armor where the bullet holes aren’t.

This is a great example of how we can fool ourselves by focusing only on the evidence in front of our eyes when there can also be important clues to be gathered by asking ourselves what evidence is missing.

(Click here for the most misleading statistic in dentistry.)

Missing patients, for example. A dissatisfied patient who leaves the practice is not likely to come in and announce they are leaving. They just stop coming. And because you are so busy with the patients in front of you, you may never stop to think about who you are not seeing or why you’re not seeing them anymore.

Maybe there are patients who are “ghosting” from the practice because they grew tired of having to schedule so many weeks out to get an appointment. I sometimes hear dentists and team members in over-saturated practices like this say that they very seldom hear patients complain about the delays in getting in. But that’s likely because those patients who are truly bothered by the delays are simply not coming back. Like those missing planes, their absence speaks volumes.

(Click here to see what makes a great experience for dental patients.)

This is one reason why I argue, as I did in this article, that it is important to be proactive about things like expanding hygiene capacity to accommodate smooth patient flow and improve retention. It’s also a reminder that sometimes the most compelling evidence is not right before your eyes. Sometimes it comes from what is not there at all.

(For more articles by Imtiaz Manji, click here.)