A vital question runs through the four chapters of the 7th ALNAP Review of Humanitarian Action: Do all of our humanitarian efforts add up to the good we intend? An additional question provides an important sub-theme: what is the role of collective action in assessing and improving humanitarian impacts? Addressing these questions, the volume explores critical issues involved in the development of mechanisms for assessing and improving the performance of humanitarian actors. The challenge is large for several reasons acknowledged by the authors in each chapter.