With growing mass migration across the globe, researchers, practitioners, educators and policy makers are increasingly faced with rising numbers of multilingual children and adults. This volume raises key issues surrounding the evaluation of language abilities and proficiency in multilingual speakers, taking into account the facts concerning the processes of learning, speaking and understanding two languages. Issues in the Assessment of Bilinguals brings together researchers working on bilingual and multilingual children and adults in a variety of multilingual settings: typically developing bilingual children, bilingual and multilingual children and adults found in classrooms, and bilingual children growing up in sociolinguistically fluid bilingual communities - making this an essential volume which raises key issues for anyone assessing performance.