In the past 20 years the field of second language acquisition has developed into an independent and autonomous discipline complete with its own research agenda. In addition, there has been an increase in the number of conferences - of both a general and a topical nature - dealing exclusively with this topic, as well as special sessions on second language acquisition as part of larger conferences. Furthermore, the field now has journals devoted exclusively to its study as well as numerous edited volumes concentrating on specific subareas. Dealing with the ways in which second languages are learned, the authors take a multidisciplinary approach by presenting research emanating from other well-established disciplines - sociology, psychology, education and linguistics. The content is limited, for the most part, to a discussion of adult second language acquisition. Designed to be used in an introductory course for undergraduate or graduate students, the authors' goal is to make the information available to students with a wide variety of backgrounds. This volume was born out of the belief that the complexities of the field can and should be brought to the attention of many students - those intending to delve further into the field and those only curious about the pervasive phenomenon of learning a second language. The companion workbook audiocassette package for this text is available under Sorace Gass Selinker.