Understanding how people learn and fail to learn second and foreign languages is increasingly recognised as a critical social and psycholinguistic issue. This book provides a synthesis of empirical findings on second and foreign language learning by children and adults, emphasising the design and execution of appropriate research. '..the comprehensiveness of the book, combined with its detailed descriptions of empirical studies and the extensive bibliography, make it an excellent reference source for readers already familiar with the field.'Applied Linguistics, Vol 17, No 3, 1996. 'One of the most useful features of this volume is its extensive and comprehensive bibliographical coverage of research in language teaching, language acquisition and related areas of applied linguistics.'Forum for Modern Language Studies, Vol XXVIII, No 3, 1992. 'I believe that instructors using the book can feel confident that students will have a balanced mainstream view of the core issues in SLA.'Issue in Applied Linguistics, Vol 3, No 2, 1992.