George Kingsley Zipf

George Kingsley Zipf was an American linguist who discovered the statistical pattern now known as Zipf's law, describing an inverse relationship between the frequency of a word in a body of text and its rank when all words are ordered from most to least frequent, so that the second most common word appears roughly half as often as the most common, the third roughly a third as often, and so on. Zipf set out this and related findings in his 1949 book Human Behavior and the Principle of Least Effort, in which he argued that this and similar statistical regularities across language and other human behavior arise from speakers and listeners both minimizing the effort required to communicate. Zipf's statistical approach to vocabulary and frequency helped establish quantitative and statistical methods as a legitimate branch of linguistic study, and the frequency pattern he described has since been observed and studied in many other domains beyond language, including city population sizes and internet traffic. Zipf spent his academic career at Harvard University.