This book focuses on conducting research on ISL, which includes developing and evaluating hypotheses about ISL outcomes and measuring its impact on students, faculty, and communities. The book argues that rigorous research is essential to improving the quality of ISL's implementation and delivery, and providing the evidence that will lead to wider support and adoption by the academy, funders, and partners. It is intended for both practitioners and scholars, providing guidance and commentary on good practice. The volume provides a pioneering analysis of and understanding of why and under what conditions ISL is an effective pedagogy.