"Part handbook and part manual, this multi-faceted volume is a treasure trove of advice on how to conduct a form of research that is central in the study of second language learning. An array of prominent researchers clarify central concepts and apply them to specific contexts. Recommended for both graduate students and more experienced researchers.”Robert DeKeyser, Professor Emeritus, University of Maryland College Park“This is a book our field has long needed. Rogers and Sato have brought together leading experts to provide a rigorous yet practical guide to quasi-experimental research in second language acquisition. A must-read.”Rod Ellis, Emeritus Distinguished Research Professor, School of Education, Curtin University“In this first edited volume dedicated to quasi-experimental research in L2 classroom learning, the contributors acknowledge its value and benefits and meticulously examine how to strengthen and enhance its methodological rigor. An impressive range of conceptual and implementation issues are discussed, recommendations proposed, and hands-on exercises included. This is essential reading for both novice and experienced L2 classroom researchers.”Nina Spada, Professor Emeritus, University of Toronto