Establishing Evidence

This chapter provides a guide to scientific evidence and explores how field experiments can be used as a scientific standard for determining what place-based policies to adopt, refine, or abandon. It also discusses what types of evidence to rely on when experiments are not possible for various ethical or pragmatic reasons. Experimentation is at the very heart of science, and relying on a scientific model for deciding how, and in what forms, the built environment should be modified is a dynamic process that can ultimately inform the efficient and effective expenditures of limited resources by policy makers. Rather than provide a treatise on the scientific method and the value of experiments, the chapter provides a short discussion of the benefits of different methods of evaluation and focuses more attention on the utility of a science-based policy agenda for changing places. The scientific model allows people to evaluate the influence that environments may have on health and safety while also encouraging them to pursue discoveries of innovative new place-based strategies that can achieve the greatest health and safety benefits at relatively low costs.