Impact measurement
Definition:
The qualitative or quantitative assessment of impact based on measured observations (using survey data or other instruments) with a control group or theory-informed estimation.
Our definition of impact measurement is informed by academic work on theory-driven evaluation. There is a school of thought that believes random control trials (RCTs) as the only true way to measure impact. Theory-driven evaluation, by contrast, views outputs and outcomes as early or visible indications of long-term outcomes, such that well-selected indicators with a good theory of change can be used to reasonably estimate impact.