Self-directed, informal learning is a less recognized and understood form of professional development. Researching informal learning is almost an oxymoron. The process of studying learning contexts, such as informal, self-directed professional development, raises new challenges for researchers. Gaining insights into self-directed professional development requires teachers' permission and active participation; it requires creating a context of trust and reflection. Science in Action is a collaboration of researchers--teachers, members of community-based science organizations, educators from community colleges and university and graduate students who worked together to create and implement an afterschool science program for upper elementary (Grades Three to Five) and middle school (Grades Six to Eight) students. In this paper, we share what we learned about the potential for collaborations, especially models like cooperative inquiry, to negotiate the interface between research and informal learning spaces. Moreover, we describe what these teachers count as professional development as well as the consequences of their experiences on their classroom practice. (Contains 1 figure.)