Trudgill posits a multi-generational model of the development of a koiné. During the first (i.e., immigrant) generation, the speakers of the contributing dialects mix, and there is some leveling. The first native-born generation of speakers continues the leveling process. However, in the instances Trudgill was able to document (e.g., first generation speakers of Tyssedal and Odda dialects of Norwegian), the speech of this generation still reflected considerable variability in use of marked forms, both between speakers and in the repertoire of individual speakers.