Editor—Dr Marlow’s interesting annotation on high frequency ventilation,1 with its pithy epigraph, adopts a common attitude to the methodology of medical research. This holds that, to be “scientific,” a study must specify a null hypothesis and then attempt, using data, to disprove it. This agrees with the writings of Karl Popper, but goes back further to the founding father of modern statistics, R A Fisher, who2 wrote: “Every experiment may …