In this Informal Science Education (ISE) community-building workshop, we will bring together established and emerging scholars in the Learning Sciences who study informal learning with established and emerging practitioners in informal learning environments (ILEs). The purpose of the conference is to build capacity and develop sustained collaboration across these two communities for the benefit of research and practice. We will hold a working conference that will result in conference proceedings and a follow-up edited book. The conference and publications will involve two related themes: (1) Building models of learning in ILEs that directly respond to concerns raised by researchers and practitioners and (2) Connecting methods of research and methods of practice in ILEs to support iterative design and evaluation of learning environments. Our proposed work builds on a series of NSF-funded consensus conferences organized by the Institute for Learning Innovation (i.e., # ESI-9254959; Public Institutions for Personal Learning: Establishing a Long-Term Research Agenda, #ESI-9803102; Free-Choice Learning: Assessing the Informal Science Education Infrastructure; and, #ESI-0318868; In Principle, In Practice: A Learning Innovation Initiative) which resulted in published volumes (e.g., In Principle, In Practice: Museums as Learning Institutions, 2007) and another recent consensus volume, The Cambridge Handbook of the Learning Sciences (Sawyer, 2006). Our Intersection project will also build on the upcoming consensus volume, Learning Science in Informal Environments: A Review of the Research Past, Present, and Future (NRC, forthcoming), the result of an18-month NSF-funded Consensus Study. While the past work articulates where we have been and sketches an outline of an ambitious research agenda for the future, our project seeks to bring together a dedicated group of people working at the intersection of the Learning Sciences and ILEs to make the long-term agenda a reality. Prioritizing areas of inquiry and seeking to establish collaborative relationships to investigate the most pressing issues will be a central outcome of our work.