Blackwell Guide to Research Methods in Bilingualism and Multilingualism
“In summary, I can think of no other text that offers such a wide range of practical advise for actually carrying out research. This guide will find a place in courses on bi- and multilingualism, in linguistic field methods and even ethnographic methods courses, as well as on the shelves of university libraries and scholars interested in this subject.”  (Journal of Linguistic Anthropology, 19 June 2013)"This book accomplishes something quite unique, in providing a background knowledge and understanding of research methodologies used in studies of bilingualism and multilingualism." (Journal of Sociolinguistics, April 2009)"Provides a comprehensive overview of research methods on bilingualism. The overview of each research method is very brief and clear." (Studies in Second Language Acquisition, 2009)