Analyses of costs and benefits require the prediction of the effects of restoration measures and the quantification of societal values. Both of these estimates are uncertain. In this report, some of the key issues related to the assessment, description and quantification of uncertainty are discussed and guidelines are provided for considering uncertainty. 

This report provides a brief overview on the representation and quantification of uncertainty in scientific prediction followed by examples of typical risks associated with river restoration that could lead to unintended, adverse effects and in more detail, how uncertainty can be considered in CEA/CBA and in MCDA.