There is increasing debate about the role that public policy research can play in identifying solutions to complex policy challenges. Most studies focus on describing and explaining how governance systems operate. However, some scholars argue that because current institutions are often not up to the task, researchers need to rethink this ‘bystander’ approach and engage in experimentation and interventions that can help to change and improve governance systems. This paper contributes to this discourse by developing a design science framework that integrates retrospective research (scientific validation) and prospective research (creative design). It illustrates the merits and challenges of doing this through two case studies in the Netherlands and concludes that a design science framework provides a way of integrating traditional validation-oriented research with intervention-oriented design approaches. We argue that working at the interface between them will create new opportunities for these complementary modes of public policy research to achieve impact.