Dramatic changes in juvenile justice have occurred in recent decades. One result has been the emergence of new policies and practices, many of which remain largely unexamined. One avenue for gaining insight into whether such policies and practices are needed or effective, as well as into how the juvenile justice system might be improved, is to tap into the perceptions of people who work within this system. Drawing on a national survey of juvenile court practitioners, the authors investigate key questions about the effectiveness of juvenile justice and discuss the implications of the study's findings for research, policy, and practice. Abstract published by arrangement with Sage Journals.