This Survey constitutes a highly detailed micro-dialectological study of spoken Irish in the Aran Islands, focusing on geographical and social variation linked to generations (older and younger age-groups), genders (male and female), and level of education. It provides for the first time ever for any language anywhere in the world an extensive analysis of a wide range of phonological and grammatical variation on a dialectal and sociolinguistic basis. In the case of the largest of the three islands, Inis Mór, the Survey includes detailed information on phonological, grammatical and lexical variation at the level of individual townlands. The geographical layout of these townlands and the strategic position of the archipelago in Galway Bay in relation to the surrounding mainlands in Connemara, East Galway and Clare lend a remarkably potent visibility to the spectrum of linguistic variation displayed in the study. As such, the Survey echoes and also builds on Heinrich Wagner's 1958-69 work Linguistic Atlas and Survey of Irish Dialects to provide an unrivalled portrait of Irish as it was spoken in Aran in the late twentieth century. Presenting a novel and ambitious exploration of complex linguistic change embedded in a social context, the Survey represents a milestone contribution to dialectology and sociolinguistics – and, indeed, to the Irish language itself – that is of international significance.