Finding ways to understand and measure our impact on everything from world peace and community cohesion to literacy and carbon dependency. Better performance and impact measurement will be a key driver in increasing the scale and effectiveness of the impact economy. For funders it will help them make more informed investment decisions. For social enterprises it will provide valuable insight into which elements of their models and practices work best, for whom and at what cost. For consumers or partners, it will help them decide where to focus their buying power or energies. This interactive workshop will share the lessons from the efforts of governments, NGOs and development networks to measure and track impact. It will start with a group discussion of why measurement is important and share lessons from experts on how to avoid common pitfalls in designing a robust metric system. It will then break into small groups to explore for the funders and social enterprises attending, ways to overcome the challenges they face in defining and measuring impact and tracking performance.