Abstract In a world where most individuals speak more than one language and most languages are in contact with other languages, the study of language in its social context must take into account language contact. Two central questions in the study of language contact and change are (1) whether social or linguistic factors are primary in predicting the outcomes of contact; and (2) whether change in the context of contact is a foregone conclusion. Quantitative studies of sociolinguistic variation provide an effective means of observing change in progress, but the majority of such studies have focused on monolingual speakers/communities. This article gives a brief summary of the study of language contact in variationist sociolinguistics before turning to a discussion of the types of data and approaches best suited to answering the question of how and when contact causes change in multilingual communities. Recognizing that the description of a multilingual community involves more social parameters and more inter‐individual variation than a monolingual one, this article focuses on a core list of social factors to consider in studies of variation and change in multilingual communities, organized so that possible intersections may also be considered.