Systems are complex and adaptive in nature. Evaluating change in these systems is as important as it is challenging. Standard experimental approaches are difficult to implement without clear treatments and they do not generate useable information as no two systems are the same. More qualitative approaches tend to raise questions as to whether questions of scale can be justified. The Agora team has been at the forefront of developing new approaches to the evaluation of systems to balance these objectives. The groundbreaking and ambitious mixed-methods approaches are serving to provide evidence to the development community on the impact of systemic approaches.