Arts projects have become an important part of community development strategies. In addition to any creative achievements, projects are expected to have positive and measurable impacts on local social capital. Funding organizations routinely demand evidence for this, and formal evaluations of projects have become a condition of investment. However, quantifying the impact of the arts in terms of social gain presents considerable difficulties, arguably greater than in any other field of evaluation. These problems are not just methodological. They also raise the question of the extent to which creative processes can – or should – be managed and controlled.