When analysts do quantitative scientific assessments of complex policy problems, they have to make many assumptions in the chain of calculations that lead to the end results. These assumptions inevitably involve - to some degree - subjective judgements by the analysts. This report offers a method for analysing the 'subjective component', or 'value-ladenness', of such assumptions. 'Value-ladenness' is not reserved for politically controversial assumptions, since there are also epistemic, non-political components in the subjectivity of choices.
The proposed method enables analysts and stakeholders to conduct a well-structured discussion on potentially value-laden assumptions and their influence on the results of the assessment. An analysis of the nature and extent of the potential value-ladenness conveys the 'weak links' in the assessment and may lead to the decision to adjust the assessment. The method furthermore offers assistance in communicating crucial assumptions.
The method was tested ex post on the indicators 'change in length of the growth season' and 'deaths and emergency hospital admittances due to exposure to ozone' in the fifth Dutch Environmental Outlook, and has led to a list of weak links in the calculation of these indicators.