The "outcome agenda"is now well advanced in public policy. Both charities and funders are familiar with the concept of giving money on the basis of impact and outcomes rather than simply services provided - this has been fundamental to the work of the New Philanthropy Capital. The aim is to improve efficiency and effectiveness, yet there has been relatively little research on the effect of using performance measures in TSO's. There are many useful lessons to take from previous work on the impact of performance measures in the public sector, but new issues to consider from a theoretical perspective, such as the effect on donor-funders. it is also important to consider the actual and likely effect in practice. In some sub sectors eg homelessness, outcomes measurement has become routine. The Outcome Star, developed by Triangle Consulting for the London Housing Foundation, has been used for several years now to track the progress of homeless people. Until recently, the primary use of the Star has been seen by charities to monitor the progress of clients and to evaluate organisational performance. as commissioners and other funders start to become interested in the Star as a measure of organisational success, it is timely to consider how the increased use of performance measures will impact on TSOs as service providers. Research will extend theoretical economic analysis of the effect of performance measures in the public sector to consider TSOs and will examine the actual effect of such performance measures in practice.