William Labov

William Labov was an American linguist widely credited as the founder of sociolinguistics, the study of language variation and change as it actually occurs in speech communities. His 1963 study of vowel pronunciation on Martha's Vineyard and his 1966 study of rhoticity across New York City department stores introduced methods for observing sound change in progress and correlating linguistic variation with social class, style and identity, replacing an older tradition that treated dialect as fixed and studied it largely through written questionnaires. He continued this line of quantitative variationist study, including extensive work on African American English, for the rest of his career at the University of Pennsylvania.