In this paper we explore approaches to intervention research viewed from a broadly conceived culturalpsychological perspective. Although scholars who adopt this perspective share a belief in the centrality of culture in human development, they may differ in how they conceive of culture and how it enters into and participates in human thought and action. We examine two cultural-psychological strategies for developing and sustaining innovative educational environments: design experimentation and mutual appropriation. Design experimentation is an approach in which researchers and practitioners collaborate to simultaneously engineer innovative learning environments and understand salient aspects of human cognition and learning. They do so by developing and implementing, in a specific educational setting, a version of a learning design and iteratively revising this design in light of results from each implementation. Mutual appropriation refers to interventions in which the nature of the intervention is not prespecified, but negotiated among participants over time. We examine these approaches by introducing two examples of university-community research and educational collaborations. The first collaboration, The Beach Boys & Girls Club, is an example of an intervention based on the principles of design experimentation, while the second, the Town and Country Learning Center, illustrates the mutual appropriation approach. Through this comparative examination of the two intervention perspectives, we endeavor to show that a mutual appropriation approach can help the field create interventions that are themselves developmental in their fundamental methodology. © 2012 by Oxford University Press, Inc. All rights reserved.