Well , if I were the gypsy and you were a lady . Would you schtup me anyway would you have my baby ! ?<| sep |> Part ThreeYou complain that your report would be dry . The dryer the better . Statistics should be the dryest of all reading , wrote the great medical statistician William Farr in a letter in 1861 . Farr sounds like a caricature of a statistician , and his prescription convey the greatest possible volume of information with the smallest possible amount of editorial colour seems absurdly illsuited to the modern world . But there is a middle ground between the statistical bullshitter , who pays no attention to the truth , and William Farr , for whom the truth must be presented without adornment . That middle ground is embodied by the recipient of William Farr ' s letter advising dryness . She was the first woman to be elected to the Royal Statistical Society Florence Nightingale . Nightingale is the most celebrated nurse in British history , famous for her lamplit patrols of the Barrack Hospital in Scutari , now a district of Istanbul . The hospital was a death trap , with thousands of soldiers from the Crimean front succumbing to typhus , cholera and dysentery as they tried to recover from their wounds in cramped conditions next to the sewers . Nightingale , who did her best , initially believed that the death toll was due to lack of food and supplies . Then , in the spring of 1855 , a sanitary commission sent from London cleaned up the hospital , whitewashing the walls , carting away filth and dead animals and flushing out the sewers . The death rate fell sharply . Nightingale returned to Britain and reviewed the statistics , concluding that she had paid too little attention to sanitation and that most military and medical professions were making the same mistake , leading to hundreds of thousands of deaths . She began to campaign for better public health measures , tighter laws on hygiene in rented properties , and improvements to sanitation in barracks and hospitals across the country . In doing so , a mere nurse had to convince the country ' s medical and military establishments , led by England ' s chief medical officer , John Simon , that they had been doing things wrong all their lives . A key weapon in this lopsided battle was statistical evidence . But Nightingale disagreed with Farr on how that evidence should be presented . The dryer the better would not serve her purposes . Instead , in 1857 , she crafted what has become known as the Rose D i a g r a mnightingaleavengingangel . co . uk ? p 462 , a beautiful array of coloured wedges showing the deaths from infectious diseases before and after the sanitary improvements at Scutari . The Rose Diagram isn ' t a dry presentation of statistical truth . It tells a story . Its structure divides the death toll into two periods before the sanitary improvements , and after . In doing so , it highlights a sharp break that is less than clear in the raw data . And the Rose Diagram also gently obscures other possible interpretations of the numbers that , for example , the death toll dropped not because of improved hygiene but because winter was over . The Rose Diagram is a marketing pitch for an idea . The idea was true and vital , and Nightingale ' s campaign was successful . One of her biographers , Hugh Small , argues that the Rose Diagram ushered in health improvements that raised life expectancy in the UK by 20 years and saved millions of lives . What makes Nightingale ' s story so striking is that she was able to see that statistics could be tools and weapons at the same time . She educated herself using the data , before giving it the makeover it required to convince others . Though the Rose Diagram is a long way from the dryest of all reading , it is also a long way from bullshit . Florence Nightingale realised that the truth about public health was so vital that it could not simply be recited in a monotone . It needed to sing . The idea that a graph could change the world seems hard to imagine today . Cynicism has set in about statistics . Many journalists draw no distinction between a systematic review of peerreviewed evidence and a survey whipped up in an afternoon to sell biscuits or package holidays it ' s all described as new research . Politicians treat statistics not as the foundation of their argument but as decoration sprayon evidence is the phrase used by jaded civil servants . But a freshly painted policy without foundations will not last long before the cracks show through . Politicians need to remember there is a real world and you want to try to change it , says Will Moy , the director of Full Fact . At some stage you need to engage with the real world and that is where the statistics come in handy . That should be no problem , because it has never been easier to gather and analyse informative statistics . Nightingale and Farr could not have imagined the data that modern medical researchers have at their fingertips . The gold standard of statistical evidence is the randomised controlled trial , because using a randomly chosen control group protects against biased or optimistic interpretations of the evidence . Hundreds of thousands of such trials have been published , most of them within the past 25 years . In nonmedical areas such as education , development aid and prison reform , randomised trials are rapidly catching on thousands have been conducted . The British government , too , has been supporting policy trials for example , the Education Endowment Foundation , set up with 125 m of government funds just five years ago , has already backed more than 100 evaluations of educational approaches in English schools . It favours randomised trials wherever possible . The frustrating thing is that politicians seem quite happy to ignore evidence even when they have helped to support the researchers who produced it . For example , when the chancellor George Osborne announced in his budget last month that all English schools were to become academies , making them independent of the local government , he did so on the basis of faith alone . The Sutton Trust , an educational charity which funds numerous research projects , warned that on the question of whether academies had fulfilled their original mission of improving failing schools in poorer areas , our evidence suggests a mixed picture . Researchers at the LSE ' s Centre for Economic Performance had a blunter description of Osborne ' s new policy a nonevidence based shot in the dark . This should be no surprise . Politicians typically use statistics like a stage magician uses smoke and mirrors . Over time , they can come to view numbers with contempt . Voters and journalists will do likewise . No wonder the Guardian gave up on the idea that political arguments might be settled by anything so mundane as evidence . The spindoctors have poisoned the statistical well . But despite all this despair , the facts still matter . There isn ' t a policy question in the world that can be settled by statistics alone but , in almost every case , understanding the statistical background is a tremendous help . Hetan Shah , the executive director of the Royal Statistical Society , has lost count of the number of times someone has teased him with the old saying about lies , damned lies and statistics . He points out that while it ' s easy to lie with statistics , it ' s even easier to lie without them . Perhaps the lies aren ' t the real enemy here . Lies can be refuted liars can be exposed . But bullshit ? Bullshit is a stickier problem . Bullshit corrodes the very idea that the truth is out there , waiting to be discovered by a careful mind . It undermines the notion that the truth matters . As Harry Frankfurt himself wrote , the bullshitter does not reject the authority of the truth , as the liar does , and oppose himself to it . He pays no attention to it at all . By virtue of this , bullshit is a greater enemy of the truth than lies are . Tim Harford is the author of ' The Undercover Economist Strikes Back '. Twitter TimHarford