The t-test, a widely used statistical method, was invented by William Sealy Gosset, a mathematician and brewer at the Guinness brewery in the early 20th century. Gosset developed the t-test to address the problem of interpreting data from small sample sizes, which was a challenge in the brewery's quality control process. The t-test allows researchers to determine whether the difference between a sample and a population is statistically significant. Gosset published his work under the pseudonym 'Student' to keep the brewery's research confidential.