In studies of environmental issues, the question of how to establish a productive interplay between science and policy is widely debated, especially in relation to climate change. The aim of this article is to advance this discussion and contribute to a better understanding of how science is summarized for policy purposes by bringing together two academic discussions that usually take place in parallel: the question of how to deal with formalization (structuring the procedures for assessing and summarizing research, e.g. by protocols) and separation (maintaining a boundary between science and policy in processes of synthesizing science for policy). Combining the two dimensions, we draw a diagram onto which different initiatives can be mapped. A high degree of formalization and separation are key components of the canonical image of scientific practice. Influential Science and Technology Studies analysts, however, are well known for their critiques of attempts at separation and formalization. Three examples that summarize research for policy purposes are presented and mapped onto the diagram: the Intergovernmental Panel on Climate Change, the European Union's Science for Environment Policy initiative, and the UK Committee on Climate Change. These examples bring out salient differences concerning how formalization and separation are dealt with. Discussing the space opened up by the diagram, as well as the limitations of the attraction to its endpoints, we argue that policy analyses, including much Science and Technology Studies work, are in need of a more nuanced understanding of the two crucial dimensions of formalization and separation. Accordingly, two analytical claims are presented, concerning trajectories, how organizations represented in the diagram move over time, and mismatches, how organizations fail to handle the two dimensions well in practice.