This book syntheses cutting-edge research on the role of individual differences (IDs) in the field of SLA and in computer assisted language learning. It also outlines the theoretical and methodological issues at the heart of this research, presents empirical findings and charts future directions of this research. Pawlak and Kruk provide an overview of the latest theoretical developments in research on IDs in SLA as well as methodological considerations that are crucial when researching individual variation, with special emphasis on data-collection procedures that are most prominent in CALL. The book goes on to summarize and explore a body of empirical evidence concerning the role of individual difference factors in CALL, singling out existing gaps, methodological problems, and areas in need of further investigation. Finally, the authors provide a guide on how empirical investigations of individual difference factors in CALL can be improved by incorporating latest developments from the broader field of SLA. This book will be of great interest to postgraduates and scholars in the domain of applied linguistics and second language education who are interested in CALL, as well as those studying and undertaking research in second language learning and teaching.