However, I still could not get fully understand about it. You may remember that when we mentioned the topic 'Is payer really help?' When we discussed would the result of that experiment not so accurate?Дuring that issue, we considered Texas sharp shooter problem as that - 'are many things being measured, and only the few positive hits being reported?' To think we can confirm our hypothesis from the same data we used to formulate our hypothesis would be to make an error analogous to a sharpshooter marking the location of the target after the shot has already been taken.This is a shortВ videoВ about Texas Sharpshooter Fallacy.ДЄctually I got really confused when we first talked about this concept in our science class. What we used to sayвЂ¦ вЂњWhat are the chances of THAT?!!вЂќ вЂњWhoa!вЂќ вЂњOh, my gosh! That just CANвЂ™T be a coincidence.вЂќ What we will (I hope) say from now onвЂ¦ вЂњThat seems interesting, but we should collect new data. The SharpshooterвЂ™s Fallacy The fallacy is characterized by a lack of specific hypothesis prior to the gathering of data, or the formulation of a hypothesis only after data has already been gathered and examined (a practice also known as вЂњData SnoopingвЂќ). A map like that is a lot like the side of the sharpshooterвЂ™s barn, and presuming there must be a cause for cancer clusters is the same as drawing bullвЂ™s-eyes around them.It looks like you have a pretty good indication of where the groundwater must be poisoned, or high-voltage power lines are bombarding people with damaging energy fields, or where cell phone towers are frying peopleвЂ™s organs, or where nuclear bombs must have been tested. If you look at a map of the United States with dots assigned to where cancer rates are highest, you will notice areas of clumping.Epidemiologists are especially wary of it as they study the factors which lead to the spread of disease. One of the reasons scientists form a hypothesis and then try to disprove it with new research is to avoid the Texas Sharpshooter Fallacy.Like the Texas Sharpshooter, someone announces that a target has been hit at which no one previously knew we were even aiming.If you are being dealt 5 cards, there is a 100% chance that one of these extremely unlikely 1 in 2.6 million events will occur.The SharpshooterвЂ™s Fallacy is at work when are astonished by the occurrence of extremely low probability events of this sort.Often this sort of astonishment is as foolish as picking up your cards at the poker table after being dealt every hand and exclaiming, вЂњMy gosh! There is only a 1 in 2.6 million chance that I would get this hand!вЂќ.вЂњThere must be something serious at work here.If you mean the chance of getting this particular hand, then the probability is 1 in about 2.6 million.If you mean, вЂњhow likely would it be to be dealt a hand with neither any matched cards, nor a straight, nor a flush?вЂќ then the chance is about 1 in 2.I mean, what are the chances?вЂќ Asking this question under many circumstances amounts to using the same data to test your hypothesis that you used to generate the hypothesis. The Texas SharpshooterвЂ™s fallacy concerns the tendency for people to attach undue significance to artifacts of randomness such as clustering, streaks, and coincidences.The more we look, the more of such differences we would find, but when you draw the bullвЂ™s-eye around the similarities вЂ“ whoa.Kennedy had lustrous auburn hair, while Lincoln wore a stove pipe hat.Kennedy was shot in Texas, Lincoln in Washington D.C.Kennedy was killed with a rifle, Lincoln with a pistol.Both men were succeeded by a man named Johnson вЂ“ Andrew for Lincoln and Lyndon for Kennedy.Kennedy was killed in a Lincoln made by Ford.

Lincoln was killed in the Ford Theater.

They were both killed on a Friday while sitting next to their wives.Both were shot and killed by assassins who were known by three names with 15 letters.Kennedy were both presidents of the United States вЂњRight where I was aiming.вЂќ Should the skeptic be impressed with the sharpshooterвЂ™s aim? He drew a circle around it and marked a bullвЂ™s eye in the center of the cluster of bullet holes. He strolled up to the barn and located the area where the bullets clustered most tightly. Then he drew his pistol and emptied it into the side of abarn from a distance of 200 feet. вЂњIвЂ™m your huckleberry,вЂќ said the sharpshooter. The Texas SharpshooterвЂ™s Fallacy There once was a sharpshooter who was challenged by a skeptic to demonstrate his skill.

Sharpshooter fallacy