The numerical analysis of multi-scale methods for materials in the static setting (quasi-continuum, atomistic/continuum coupling, QM/MM) has reached an advanced state. By contrast, the numerical analysis of coarse-grained molecular dynamics, e.g., CGMD, hot-QC, bridging scale methods, and Mori-Zwanzig-based methods is essentially open. In this working group, we plan to review different approaches to coarse-grained MD, such as information-based methods, formulate concrete and ideally tractable mathematical questions, and explore some of the available mathematical techniques. The format will be a mixture of mostly informal presentations and small-group discussions.