Foreword: This year's annual conference on criminal justice research and evaluation is a milestone of sorts. Some 30 years ago, the President's Commission on Law Enforcement and Administration of Justice noted with alacrity that the revolution of scientific discovery had "largely bypassed the problems of crime and crime control." The method of objective analysis that had been used with stunning success to raise living standards, help people live healthier lives, and explore the heavens had unaccountably failed to be applied to one of the era's most pressing problems. To the great good fortune of succeeding generations, the Commission in its wisdom recommended creation of a Federal research agency dedicated to the scientific study of crime and criminal justice, with the aim of informing and aiding the work of practitioners. The National Institute of Justice, the agency established by Congress to carry out that mission, has for the past three decades been seeing the returns on that investment multiply. Criminology has become a respected field of scholarly inquiry, and we have built an impressive body of knowledge that has helped us better understand criminal behavior and the justice system. More important, the results of scholarly inquiries have been and are being applied to the day-to-day operations of law enforcement, corrections, the courts, and other elements of the justice system. In the conference, which revisited the Commission with the theme "Enhancing Policy and Practice Through Research," we saw how the investment continues to yield returns. The plenary sessions in particular emphasized praxis-research put to the service of real-world situations. Because of the distinctiveness of this year's plenary panels, we decided to publish them in three separate volumes: viewing crime from the street level, addressing school violence through research-based policy developed through an interdisciplinary approach, and understanding the involvement of women and girls in the criminal justice system. Sudhir Venkatesh and Richard Curtis bring the ethnographer's perspective to the analysis of street crime, analyzing, respectively, the financial activity of gangs and recent trends in drug dealing. Their method, distinct from that of conventional quantitative social science, calls for intensive observation over long periods and involves the quest for what is a a iv specific to single places and times and what is generalizable. The close-up, street-level observations of study subjects offer singular insights for practitioners who deal with these individuals as offenders. In this panel, we also benefited from the perspective of Charles Ramsey, Chief of the Metropolitan Police Department, Washington, D.C. His indication that drug trafficking and gang crime persist in his jurisdiction despite the overall drop in crime offers proof of the ethnographer's caution against facile generalization. This year marks the first time the program offices of the Office of Justice Programs (OJP)-the Corrections Program Office, the Drug Courts Program Office, the Executive Office for Weed and Seed, and the Violence Against Women Office-have joined the OJP bureaus as conference sponsors. Because these offices work so closely with the practitioner community, I feel their sponsorship is an added expression of their commitment to research. I think they would endorse Chief Ramsey's succinct assessment of the role of research in affecting crime levels in the years to come as bringing to light findings useful for fashioning real-world solutions. "The best way to predict the future," the Chief said, "is to help create it." Those who wish to read more can find abstracts of the conference sessions on the World Wide Web at http://www.ilj.org. Jeremy Travis, Director National Institute of Justice.