Evaluating environmental change strategies: challenges and solutions.

In this introductory article we define environmental change strategies (ECS), summarize the primary challenges associated with evaluating ECS, and provide an overview of the methods researchers have employed to begin to address these challenges. This special issue provides a range of examples, from researchers and practitioners in the field, of different approaches for addressing these challenges. These articles present new methods to understand and test how ECS are implemented and propose methods to evaluate their implementation. The content of the articles covers multiple public health issues, including substance abuse prevention, tobacco control, HIV prevention, and obesity prevention. This special issue is intended to build the evidence base for effective ECS, generate compelling discussion, critical analyses, and spur future research that will help improve the implementation and evaluation of ECS.