As soon as we invite our only intuition to reason, it continually misleads us. Grasping reality is far too complex to be a simple personal affair and its non-obvious nature forces us to take advantage of previous discoveries. Let me convince you with some examples.
During the Second World War, the Allies sought to reinforce their aircraft. In order to study their fragility, they drew up a plan of the impacts of enemy projectiles. They first considered strengthening them in the places that had received the most impacts, but a mathematician named Abraham Wald suggested the opposite. Only the planes pierced like on the plan had returned to their base, those hit differently had not returned. Consequently, it is better to reinforce the untouched parts of the plan (engines, cockpit, etc.) which are essential for flying, as experience has shown that the bullet-screened parts were actually much less critical.
Quantity Trumps Quality
The ceramics teacher announced on opening day that he was dividing the class into two groups. All those on the left side of the studio, he said, would be graded solely on the quantity of work they produced, all those on the right solely on its quality. His procedure was simple: on the final day of class he would bring in his bathroom scales and weigh the work of the “quantity” group: fifty pound of pots rated an “A”, forty pounds a “B”, and so on. Those being graded on “quality”, however, needed to produce only one pot - albeit a perfect one - to get an “A”.
Well, came grading time and a curious fact emerged: the works of highest quality were all produced by the group being graded for quantity. It seems that while the “quantity” group was busily churning out piles of work - and learning from their mistakes - the “quality” group had sat theorizing about perfection, and in the end had little more to show for their efforts than grandiose theories and a pile of dead clay.
Art & Fear – found in codinghorror
Lie to Teach the Truth
Principles for Better Teaching explain how reality is complex, too complex to be digested all at once, which leads great teachers to lie in class.
Bad teachers always want to be absolutely accurate at the cost of being incomprehensible. Good teachers, on the other hand, prefer to be understood by their students at the cost of sometimes over-simplifying reality or even lying.
The Slower the Faster
A good software engineering practice consists in investing a lot of time and energy in testing. When skipped, the rapid early development suddenly becomes slow or even blocked. To deliver features at a higher speed in messy code, you must first slow down significantly, focus on testing and refactoring before you can expect any speed improvement.
I hope I have succeeded in convincing you that, with our intuition alone, we would fail to explain many phenomena. To avoid pitfalls, we rely heavily on the expertise of others to guide us towards better responses. A good reason to be humble.
Do you think a non-intuitive example is missing? Send me your comments! This list will certainly be extended and refined, subscribe to the newsletter if you wish to be notified about it.