Across the social sciences, there are scores of books on research methodology. Some are written from a particular epistemological position; others promote mixed methods that include experiments and surveys, ethnomethodological and action research, case studies and biography.Across bilingualism and multilingualism, there are even more books derived from inside disciplines such as linguistics, psycholinguistics, sociolinguistics and education, but also from politics, history, child psychology, cognitive psychology and, increasingly, neuroscience. A few books are multidisciplinary; very few inter-disciplinary.A book that combines research methodology and bilingualism/ multilingualism needs to have a value addedness that transcends both traditions. It cannot just repeat advice about research strategies and research tools that are present in research-methods books. Nor can it narrowly discuss research on bilingualism and multilingualism. It has to connect the two, such that both are exalted. It has to integrate so that researchers on bilingualism and multilingualism are truly educated well beyond the standard textbooks on research methodology and bilingualism. Such a book has to have two integrated subjects and no predicates. It has to avoid parading one tradition, with the other as an annex. Does this book succeed in integration?There are 22 chapters, with a fairly comprehensive and detailed coverage of different research methodologies in bilingualism. It concentrates on three perspectives, namely linguistic, psycholinguistics and sociolinguistic. Some research traditions that surround bilingual education, for example, are not mentioned. In particular, the action research tradition that has become so strong education, involving intervention and change, is absent. This serves to make the book strong on theory and pure research; weak on bilingualism in practice -where research is also crucial for evidence-informed policy and provision.Some chapters concern standard-research-methodological topics such as sampling, experimental design, interviewing, brain imaging, questionnaires, transcription, statistical analysis, ethnography, critical discourse analysis, project development and dissemination. Other chapters are closer to the subject C