The European Research Council (ERC) is the first European funding body set up to support the best-of-the-best scientific efforts in Europe across all fields of science and engineering. It encourages the work of independent top researchers in Europe and rewards innovative proposals, channelling funds to the most promising researchers in many fields. It is essential for the EU to analyse the impact of such an organisation and assess its effectiveness in achieving its aims. To address this need, the EU-funded project 'Understanding and assessing the impact and outcomes of the ERC funding schemes' (Eurecia) is developing a new framework to understand better the dynamics of the European science system and the activities of the ERC. The project is assessing the impact and outcomes of the ERC's funding schemes and their interaction with national and international governance. It will also analyse data on researchers, research organisations and funding organisations. Once the analyses are completed, a panel of experts will discretely assess to what degree the ERC is achieving its expected outcomes and impact. The project team defines impact as 'a clearly attributable difference over time', and the team is looking for both intended objectives and unintended impact of the ERC funding schemes. In light of this, the project and involved research are being structured around three framework issues: how to measure impact, how to attribute impact and how to assess impact. Measuring impact is challenging in science. It must draw on theories and concepts from the sociology of science and political science among other disciplines. Eurecia is developing methodology to measure the impact of the ERC funding schemes in five distinct but interrelated aspects of the science system. These are researchers, research and careers, knowledge communities, research organisations, the European funding landscape, and national funding landscapes. Furthermore, the project incorporates two cross-cutting themes, those of science governance and science dynamics. A combination of research methods including surveys, cases studies and in-depth interviews, is being applied to achieve the project's goals. Eurecia expects that its findings will reveal how impacts vary across different funding landscapes, organisations and research fields. This is why the study must cover universities, research organisations, research funders and researchers - stakeholders interviewed in nine European countries. Once the results are out, Europe will have a much better understanding of how this funding is helping research across the continent. It will also be able to fine-tune funding mechanisms to achieve even optimal results.