On Monday 03 Oct 2011 4:51:12 pm Udhay Shankar N wrote: > Fascinating. Will the next ruling ban inductive logic as well?
I don't know what inductive logic means, but here are three views (at the bottom of this post) from the article. I disagree with the mathematician and agree with the psychologist and lawyer. The judge IMO is right. Statistics is abouut probability. The law is all about being "innocent until proven guilty". If it was one's own ass in the firing line - or that of a dear one such as a wife or a husband one would certainly support the "innocent until proven guilty" attitude. We are taught to expect precision from mathematics. 2 x 2 = 4 . Period. We would never condone an airline pilot for landing in Karachi instad of Mumbai because he was unable to feed in the coordinates for navigation. 27 x 67 is exactly 1809. It is not "approximately" 1800, or "nearly 2000" Humans continuously make guesstimates like "nearly 2000" or "approximately 1800". Pilots can navigate by dead reckoning and the position of the sun, but they frequently get lost. If you use mathematics the lay person expects certainty, not a propability. Any fool and his uncle would be able to come up with guesswork, hunches and probabilities. Now if a mathematician tries to convince me that his method "probability" and how he derives his gut feeling is "mathematical" and better than mine it is bullsh1t if it is not exact. I can do guesswork too. A whole lot of astrology is based on probabilities. We just don't want to believe it. It's too far fetched. But statistics is astrology based on information that we can relate to and ends up being more "credible" than astrology. It still deals only with probabilities and likelihoods. If you want to gamble your money, use statistics over astrology if you like. But when it comes to putting someone in jail, neither astrology nor hi funda statistics cut it. Mathematician: > "The impact will be quite shattering," says Professor Norman Fenton, a > mathematician at Queen Mary, University of London. In the last four > years he has been an expert witness in six cases, including the 2007 > trial of Levi Bellfield for the murders of Marsha McDonnell and Amelie > Delagrange. He claims that the decision in the shoeprint case threatens > to damage trials now coming to court because experts like him can no > longer use the maths they need. > Psychiologist: > "It's potentially very damaging," agrees University College London > psychologist, Dr David Lagnado. Research has shown that people > frequently make mistakes when crunching probabilities in their heads. > "We like a good story to explain the evidence and this makes us use > statistics inappropriately," he says. When Sally Clark was convicted in > 1999 of smothering her two children, jurors and judges bought into the > claim that the odds of siblings dying by cot death was too unlikely for > her to be innocent. In fact, it was statistically more rare for a mother > to kill both her children. Clark was finally freed in 2003. Lawyer: > Lawyers call this type of mistake the prosecutor's fallacy, when people > confuse the odds associated with a piece of evidence with the odds of > guilt. Recognising this is also what eventually quashed the 1991 > conviction for rape of Andrew Deen in Manchester. The courts realised at > appeal that a one-in-three-million chance of a random DNA match for a > semen stain from the crime scene did not mean there was only a > one-in-three-million chance that anyone other than Deen could have been > a match – those odds actually depend on the pool of potential suspects. > In a population of 20 million adult men, for example, there could be as > many as six other matches.
