This chapter describes the scope and nature of design and measurement strategies that can produce practice-based evidence. It discusses tools for researchers to address the tasks of problem definition, measurement, causal processes, and generalization. The chapter deals with an extended example of developing practice-based evidence in community-based youth justice organizations in New York City. It focuses on the four basic dimensions of research tools and discusses how these might be applied to develop practice-based evidence on an important and evolving intervention in policing. The generation of practice-based evidence draws on a wide range of research designs and measurement strategies. All research raises questions of measurement, something that is critical for research on policing. Some types of police-generated data are most commonly used for measures of crime or public safety. Other important strategies are surveys and observation. The discussion of these concepts may seem a bit pedantic at times, especially to more experienced researchers.