Special issue on expert judgement

We are indeed gratified to be able to present eight impressive papers on the subject of expert judgment. It is well-known that the calls for taking uncertainty more seriously in quantitative decision support, at all levels, become ever more persistent (as examples we may mention [1]). Quantifying uncertainty means, proximally and for the most part, using structured expert judgment. The qualifier “structured” means that expert judgment is treated as scientific data, albeit scientific data of a new type. Elicitation and representation of uncertainties, processing the expert judgment data, and utilization of results must be subjected to transparent methodological rules grounded in the scientific method itself. The first article announces the availability of the TU Delft expert judgment database to all researchers in these field. Three other articles in this volume illustrate the use of these data. The articles will be mentioned and briefly summarized in the order of their appearance.