These volumes present a number of solutions to the problems of studying variability in second language acquisition. The contributors combine insights from recent research in a number of fields - quantitative sociolinguistics, discourse analysis, pragmatics, psycholinguistics, language typology, social psychology, the sociology of language, ethnomethodology, pidgin-creole studies - which expose the richness of approaches represented in the volumes. A generalized view of second language acquisition, sensitive to both socio- and psycho-linguistic issues emerges, enabling the reader to see more directly the relevance of second language acquisition studies to the central questions of language.