What is the potential of a process-oriented or praxeological methodology as outlined in our other contribution to this volume (Chapter 7)? What kind of empirical results does such a methodology generate? What is the relevance and scope of object theories¹ developed on the basis of reconstructive methods? In this chapter, we answer these questions by focussing on some well-confirmed research results that build up to a theory of adolescent actionism. We thereby draw on several systematically related large-scale studies based on over hundred cases (individual persons and groups) in total.² We single out individual cases to exemplify the studies in order to vividly illustrate the research practice. Methodical comments are restricted to a minimum in favour of demonstrating the unfolding of the object theory—in this case: the theory of actionism—and its embedding into a comprehensive theory of adolescent development. Two process structures—a situational and a biographical one—will be central in developing the argument: actionism and the phases of adolescent development.³