Theory-based impact evaluation

This document is part of the ‘Better Evidence in Action’ toolkit.

There are several different approaches to theory-based evaluation — including contribution analysis, realist evaluation and process tracing — and each has its own terminology. The common factor is that they all rely on generative causation. In other words, they depend on identifying the mechanism that explains effects. They also have two key stages: conceptual and empirical. In the former, researchers work with local stakeholders to develop or reconstruct the causal mechanism and use it to guide their evaluation; in the latter, they test the mechanism to investigate how their observed outcomes came about.