Development organizations are pressed to demonstrate that their programs result in significant lasting changes in the well-being of their intended beneficiaries. However, such “impacts” are often the product of a confluence of events for which no single agency or group of agencies can realistically claim full credit. As a result, assessing development impacts is problematic, yet many organizations continue to struggle to measure results far beyond the reach of their programs. Outcome Mapping is one methodology used to address this issue. The originality of this approach lies in its shift away from assessing the products of a program to focus on changes in behaviour, relationships, actions, and activities in the people, groups, and organizations it works with directly.