Rationality and effectiveness: does EIA/SEA treat them as synonyms?

This article discuss the notion of effectiveness by employing a critical theory understanding of rationality, which recognizes three different types: cognitive-instrumental, moral-practical and aesthetic-expressive. This distinction is important for understanding effectiveness in environmental assessment. Furthermore, such understanding has to do with whether impact assessments can protect environmental values or not. Both terms - rationality and effectiveness - are frequently and vigorously used in theory and discussion on environmental assessment practice and development; they are also widely used synonymously, albeit often unconsciously. In outlining such confusion, the article also discusses so-called post-rational approaches to environmental assessment. Finally, from these theoretical clarifications and detailing of concepts the implications for environmental assessment practice are outlined.