Langages - Année 1992 - Volume 26 - Numéro 108 - Pages 5-15This paper evaluates the theoretical importance of Labov's conception of language : 1) his historical sources around the concepts of variation, variable and variant, including the relationships with dialectology, the Prague School and Martinet ; 2) the way in which his novel concepts of structured heterogeneity, inherent variability and vernacular speech build a specific theoretical construct which can account for variation and change. 11 pages Source : Persée ; Ministère de la jeunesse, de l’éducation nationale et de la recherche, Direction de l’enseignement supérieur, Sous-direction des bibliothèques et de la documentation.