Book excerpt: This volume offers a comprehensive snapshot of the breadth of empirical research currently being conducted on the second language acquisition of sociolinguistic variation in Spanish during study abroad. Research on this topic spans diverse methodological approaches, types of programs, linguistic structures, and learner characteristics, which is reflected in the contributions in this volume. This diversity of approaches illustrates how the second language development of sociolinguistic variation during study abroad depends crucially on a number of linguistic and extralinguistic factors and can be measured in distinct ways. Thus, this collection will be an indispensable resource to researchers and students of second language acquisition, sociolinguistics, applied linguistics, education, and other fields interested in language development during study abroad.