Implementation science is one of a number of “sciences” to have emerged in the past few decades to tackle one of the most important problems associated with the delivery of health and social services in our time, that is, the 17-year gap between the identification of a priority for service delivery that promises better outcomes at less cost, and the routine use of that service. People in need of such services generally cannot afford to wait that long to receive them. Even then, we devote so much time, energy and resources to developing these services and then creating an evidence base using costly randomized controlled trials, only to have the routine use of these services more the exception than the rule. The problem often lies in a failure to understand and address the potential barriers to the implementation and sustainment of these evidence-based services and policies, known in this book as evidence-based practices or EBPs.

The task of changing the behavior of individual practitioners and service organizations for the sake of EBP implementation has drawn upon a number of theoretical traditions associated with an array of disciplines, including rural sociology, cultural anthropology, social work, organizational psychology, management science, public health, and social psychology. The model introduced in this book draws from transactional theory as represented in the work of anthropologist Frederick Bailey. However, while Bailey focused on transactions as a source of political gain and competitive struggle, the model advanced in this book sees social change as a bidirectional process in which both parties in a transaction exchange one thing in order to receive something else. In this instance, the social change is successful implementation observed in research conducted in child welfare and child mental health by the author in the past decade. The argument advanced in this book is that in order to change the behavior of the individual practitioners and organizations in these systems of care, or in any health and social service system for that matter, researchers and EBP developers must be willing and able to change themselves. Further, that change manifests itself through a series of transactions in knowledge, attitudes and practices that occur through social relationships between researchers, practitioners and policymakers, and the emergence of a set of shared understandings or common “culture of implementation” linking all participants in this endeavor.