Contribution analysis is a useful evaluation methodology that helps iteratively map evidence against a theory of change and understand to what extent observed outcomes are a consequence of a particular activity, as opposed to other factors. As an example, this evaluation commissioned by the Centre for International Forestry Research shows how research work influenced the sustainability of forest management in the DRC. Using contribution analysis, the evaluation was able to trace several causal pathways through a complex interaction between groups showing how these were derived from evidence.