Methodological lessons and findings from an impact evaluation of a WASH project in Indonesia

Internationally, there is growing emphasis on evaluations that aim not only at output and performance data but also show the project’s impacts. This paper reports on the experiences, findings and lessons from the impact evaluation of the Second Water and Sanitation for Low Income Communities Project (WSLIC-2) in the Ministry of Health of Indonesia. During project formulation an impact study was planned using the strongest model of a double difference evaluation (differences between before and after situations and practices in project and matched control villages). In this paper, the team that designed and implemented the study reports on the problems and how they were addressed, followed by a brief summary of the findings. It concludes that the classical double difference study is becoming ever harder to practice in development research and suggests ways to address the challenge.