The 19th-century European notion of the one people-one language nation as the ideal state has been a very pervasive influence in spite of the fact that most countries in the world today are multilingual, that is they contain ethnic groups in contact and not infrequently in competition. Such thinking has held implications for the setting of language policies, from hanging a wooden clog around the neck of a child heard speaking Occitan in Southern France to the considerable budgeting in Ireland for the promotion of Irish. In this book, Paulston presents an analytical framework for explaining and predicting the language behaviour of social groups as such behaviour relates to linguistic policies for minority groups. She argues that a number of factors must be considered in the understanding and establishment of language policies for minority groups: (1) if language planning is to be successful, it must consider the social context of language problems, (2) the linguistic consequences for social groups in contact will vary depending on the focus of social mobilization, i.e. ethnicity or nationalism, and (3) a major problem in the accurate prediction of such linguistic consequences lies in identifying the salient factors which contribute to language maintenance or shift, i.e. answering the question “under what conditions?”.