The time-honoured study of dialects took a new turn some forty years ago, giving centre stage to social factors and the quantitative analysis of language variation and change. It has become a discipline that no scholar of language can afford to ignore. This collection identifies the main theoretical and methodological issues currently preoccupying researchers in social dialectology, drawing not only on variation in English in the UK, USA, New Zealand, Europe and elsewhere but also in Arabic, Greek, Norwegian and Spanish dialects. The volume brings together previously unpublished work by the world's most prolific and well-respected social dialectologists as well as by some younger, dynamic researchers. Together the authors provide new perspectives on both the traditional areas of sociolinguistic variation and change and the newer fields of dialect formation, dialect diffusion and dialect levelling. They provide a snapshot of some of the burning issues currently preoccupying researchers in the field and give signposts to the future direction of the discipline.