Printed in Great Britain The Role of the Statistician

Statistics has been called the technology of the scientific method yet medical research is often criticised for ignorance and misuse of statistics.1'2 Examples include incorrect use of statistical methods,3 inadequate sample sizes4 and poor reporting of study design and analysis.5 In epidemiologies! research and clinical research based on populations there is a particularly strong need for good statistical input. In studies involving free-living humans simple, tightly controlled laboratory experi-ments are often impossible and sophisticated study designs are needed because of the multiple sources of systematic and random error. Also, these studies tend to generate complex data sets. For these reasons it is unwise for epidemiologists and clinical researchers to embark alone upon such research or to seek insufficien