Abstract: How are representations of violence influenced by the ‘agency of data’, in other words the social practices of data collection, analysis, dissemination, and practitioner reception? The DATAWAR project builds on the hypothesis that scientific output in quantitative conflict studies is driven less by theoretical innovation than by the ‘politics of data’: the availability, reputation, and mathematical malleability of numerical observations of conflict. We anticipate that the perceptions of conflict developed by practitioners who employ quantitative methods and sources are prone to distortion as a result of the nature of the available data, the type of mathematical models used to analyse and potentially ‘predict’ conflict, and reliance on a selective subset of theoretical approaches. DATAWAR will carry out the first systematic investigation of scientific practices in the field of quantitative conflict studies as well as the impact of these practices on practitioners’ vision of war, covering the full lifecycle of conflict data, from collection and analysis to their use and dissemination by military and diplomatic institutions, humanitarian organisations, and the media. The unique, cross-actor and cross-national perspective of DATAWAR aims to improve our understanding of the interactions between scholarly and applied uses of conflict data, beyond the established div ide separating ‘data pessimists’ and ‘data optimists’.