As the title suggests, this book is about the prospect of a social turn in the field of second language acquisition (hereafter SLA), in particular that part of SLA which is devoted to the Input-Interaction-Output (IIO) model, as elaborated by researchers such as Susan Gass (1997; Gass and Selinker 1994/2001) and Michael Long (1996). The overall aim of the book is to examine critically some of the basic notions and assumptions which underpin this model and to suggest a more interdisciplinary and socially informed approach to SLA research. In subsequent chapters, I attempt to achieve this aim by first situating this model historically and then by unpacking what is meant by the 'S', the 'I' and the 'A' in SLA.

Before undertaking that ambitious task, I would like to use this introduction to provide some necessary background for this book. First, I attempt to situate discussions about basic ontological and epistemological issues in SLA in the more general context of changes taking place in sociolinguistics and debates about the future of applied linguistics. I then go on to examine briefly some of the recent discussions about SLA, in particular how some authors have challenged the more orthodox psycholinguistic bias of the field, suggesting that a more socially informed approach would be preferable. The final section of the introduction provides the reader with a brief overview of the content of Chapters 2–6, before ending with some caveats which I think are in order.

1.1 THE SOCIAL TURN IN APPLIED LINGUISTICS: FOLLOWING THE LEAD OF SOCIOLINGUISTICS

As I stated above, the chief aim of this book is to explore the extent to which SLA researchers, in particular those working according to the Input-Interaction-Output (IIO) model, might adopt a more interdisciplinary and socially informed approach to their research. Such a shift in approach would require SLA researchers to take a cue from recent debate about the present and future of applied linguistics (hereafter AL).