At CHESS the humanities engage the sciences and society to promote knowledge for use. What kinds of academic knowledge — 'science' in the German sense — can best inform policy and practice, what methods will produce this knowledge and how should this knowledge be put to use? Special areas of focus are causal modelling, evidence-based social and economic policy, development of tools for scientists and the use of science, models for information synthesis and practical inference, uncertainty and risk in contemporary astrobiology, and objectivity (especially for social activist research, and general issues about the role of values in science).