A century of t-tests

One hundred years ago, an author under the pseudonym of Student published a paper which was to become famous. It was entitled The probable error of a mean. But what we now know as Student's t -test attracted little attention. It took another statistician of genius, R. A. Fisher, to amend, publicise and make it ubiquitous. But both Student's and Fisher's published versions were based upon faulty data. Stephen Senn reminds us of the third dedicated researcher and the quarter of a century delay before the story behind Student's t -test emerged.