On the other hand, both agendas also raise the demand for disaggregated impact statements since the “leave-no-one-behind” principle advocates measuring effects at an individual or household level. Thirdly, impact evaluations are supposed to deliver results in a timely manner and thus enhance policy relevance. Whilst all impact evaluations aim to (quantitatively) answer the question “to what extent” results were achieved, the focus has broadened over the past few years to also include questions on “how”, “why” and “under which circumstances” an intervention caused an effect. Evidence-based policy making requires both, knowing the impact and understanding the underlying causal mechanisms.

Reflecting the complexity of the real world

Hence evaluations are facing the challenge of higher expectations regarding the number and types of questions that have to be answered while also backing the answers with quantifiable evidence. In response to the difficulty to meet all these requirements, the evaluation profession deepened the trenches between ostensibly opposing methodological (and epistemological) camps.