The document discusses evaluating the effectiveness of impact assessment instruments and theorizing their political constitution. It explores how impact assessments can be politicized and the implications for evaluation theory. Impact assessments are seen as political in how they frame issues, draw boundaries around policy debates, and influence the representation of societal issues. Science is also viewed as a political culture that shapes policy framing and interpretation. The document calls for effectiveness evaluation to take a learning approach that gives voice to plural perspectives and promotes learning through deconstructing and analyzing different meanings and interpretations.