What is action research and what are its benefits for social science? How has it developed and who is applying it? How can action research be both a method and a philosophy in research? In this text, the author reflects over her application of the method and what makes it particularly useful and discusses the benefits of collaborative approach to research. The issue is discussed from the point of view of social science research and in the light of a decade of research on and among urban social movements in Sweden and elsewhere. Action research is partly a critique of the view of how knowledge is created and used in the social sciences. It opposes the monopoly of academic institutions over the creation of knowledge and emphasizes that knowledge created in action research has changed the world in more positive ways than research created with conventional methods. The author argues that researchers in the social sciences have a responsibility and obligation to return parts of their research to those they research.