Various economic valuation techniques and Multi Criteria Decision Aid (henceforth MCDA)
methods seek to identify and evaluate the environmental impacts in aquatic ecosystems for
the improvement of the decision making process. Despite the latter's ability to respond
more effectively to the task of confronting environmental problems thanks to its
multidimensional structure, strong criticism is levelled against the obscurity prevalent in
the way the social preferences are elicited and certain criteria and weights are adopted. In
the present paper, the Focus Group technique, complemented by Content Analysis, are
applied in order to strengthen the pluralistic concept of MCDA approach and enhance the
social learning in decision making processes. The analysis was accomplished within the
framework of the EUROCAT project (European Catchments: Catchments Changes and their
impacts on the coast), and was applied to the delta area of the Axios transboundary river in
Northern Greece.