This synthesis study highlights major changes in methodology and standards of evidence in impact assessment that have taken place over the past decade, taking as its starting point the publication of the landmark report When will we ever learn? Improving lives through impact evaluation by the Center for Global Development (CGD).

The study draws on the contributions of many researchers whose work was funded under the Strengthening Impact Assessment in the CGIAR (SIAC)  program which SPIA ran from 2013 – 2017. Rather than summarizing that body of work, it synthesizes some of the key insights on methodology that the SPIA team gleaned from their involvement. It is recommended to research managers, science leaders and research scientists of all disciplinary backgrounds.

This research was supported by ISPC-SPIA under the grant “Strengthening Impact Assessment in the CGIAR (SIAC).”


Stevenson, J., Macours, K., & Gollin, D. 2018. The Rigor Revolution in Impact Assessment: Implications for CGIAR. Rome: Independent Science and Partnership Council (ISPC).


Stevenson, J., Macours, K., & Gollin, D