On a recent visit to the Guinness brewery in Dublin I almost walked past a small plaque dedicated to the chief brewer and statistician William Sealy Gosset. Anyone who has taken even a high-school statistics course has heard of Student’s T-test. But not many know that the eponymous “Student” was this brewer from Dublin.
Gosset was hired by the Guinness brewery straight out of Oxford. From the start his theoretical work was motivated by the practical problems of brewing. In the beginning of the 20th century the annual production at Guinness was ramping up towards a billion pints. At such volumes brewers could not inspect every batch of hops and malt extract. Yet, making a product of uniform quality was essential to keeping customers happy. How then to make sure that a big batch of hops was good enough from a few samples? How many measurements of malt extract were needed to ensure that the resulting beer would have the desired alcohol content?
Gosset realized quickly that answering these questions required a mathematical approach. However, existing methods did not apply to the problems he was facing. Chemists and brewers wanted to keep the number of measurements and experiments low to save money and time, while statistical methods of the day applied to large sample numbers. To develop a new approach Gosset spent a year in London at the laboratory of Karl Pearson, the foremost statistician of that time. The result was the Student’s T-test which can be used even with small sample sizes.
But why wasn’t the test named after Gosset himself? The problem was that employees of the Guiness company had revealed trade secrets in earlier scientific publications. After some discussion, Gosset was only allowed to publish his results under a pseudonym. As the publications never mentioned brewing or chemistry, it was unlikely that competing breweries would have paid attention. The modest Gosset didn’t seem to mind. He published all but two manuscripts during his life under the pseudonym “Student”.
Gosset stayed with the Guiness company for the rest of his life, ending his career as Head Brewer of a London branch. However, he was not a scientific recluse. He kept a lively correspondence with the best statisticians of the time, and helped to develop the foundations of statistics as we know it today. He had virtually no enemies, even in that time of acrimonious disputes between outsized personalities in the field. His contemporaries described him as a generous man without a “jealous bone in his body”.
Even a century ago people spoke of “lies, damn lies, and statistics”. And now, as then, statistics is frequently used to score political points and sway public opinion. But we use the work of Gosset and other statisticians today in areas too numerous to list — not just the brewing of beer! We rely on their ideas to see whether new drugs work, and to find planets around distant stars. And the quality control methods that Gosset pioneered are essential for large-scale industrial production. His mathematical ideas help us feed and clothe the world of today.
I recommend the work of Stephe Ziliak for an in-depth discussion of W. Gosset’s contributions to the development of statistics, his discussions with R.A. Fisher and other statisticians of the day, and his opinions about interpreting statistical tests. Here is a good example.