Developing a new specialization—Integration and Implementation Sciences—may be an effective way to draw together and significantly strengthen the theory and methods necessary to tackle complex societal issues and problems. This paper presents an argument for such a specialization, beginning with a brief review of calls for new research approaches that combine disciplines and interact more closely with policy and practice. It posits that the core elements of Integration and Implementation Sciences already exist, but that the field is currently characterized by fragmentation and marginalization. The paper then outlines three sets of characteristics that will delineate Integration and Implementation Sciences. First is that the specialization will aim to find better ways to deal with the defining elements of many current societal issues and problems: namely complexity, uncertainty, change, and imperfection. Second is that there will be three theoretical and methodological pillars for doing this: 1) systems thinking and complexity science, 2) participatory methods, and 3) knowledge management, exchange, and implementation. Third, operationally, Integration and Implementation Sciences will be grounded in practical application, and generally involve large-scale collaboration. The paper concludes by examining where Integration and Implementation Sciences would sit in universities, and outlines a program for further development of the field. An appendix provides examples of Integration and Implementation Sciences in action
