School violence became a topic of broad national concern in the United States in reaction to a series of tragic school shootings during the 1990s. Efforts to understand and prevent school shootings have stimulated the rapid development of a broader interest in school safety with an emerging multidisciplinary research agenda. The maturation and fulfillment of this research agenda require that researchers critically examine their research methods and measurement strategies. This article introduces a volume that examines fundamental methodological and measurement issues in the rapidly expanding body of research on school safety and violence. The authors hope to stimulate greater attention to methodological pitfalls and critical measurement issues that hinder research progress in several related areas, including the uncertain reliability and validity of self-report surveys used to measure high-risk behavior and bullying, the limitations of discipline referral databases as a source of information on school climate, and the overly narrow focus on relatively infrequent critical incidents of violence, often at the expense of a more comprehensive and multifactorial examination of the school environment.