Chester Ittner Bliss

Chester Ittner Bliss (1899-1979) was an American biologist whose main legacy lies in statistics. Born in Springfield, Ohio, he studied entomology at Ohio State University and took his doctorate at Columbia University in 1926, learning most of his statistics on his own while solving problems in pest control. In a 1934 article in Science he introduced the probit, a probability unit used to transform the percentage of insects killed by a pesticide. In 1939 he described the approach now called Bliss independence, a reference model for judging synergy between drugs. He also worked with Ronald Fisher on an iterative method of maximum likelihood for probit bioassay, coined the term rankit, was elected a Fellow of the American Statistical Association in 1942 and served as first secretary of the International Biometric Society.