[en] Risk and uncertainty analyses often require the use of expert judgment to quantify uncertain parameters or assign probabilities to events. In this role, expert judgment serves as a device to integrate disparate sources of information and provide input into the analysis in a form that can be combined with other sources of information such as observational or experimental data. The collection of expert judgments should not be made in an haphazard manner. Such an effort deserves a carefully thought through design and proper execution. It is the purpose of this paper to provide a discussion of the main considerations in establishing an expert judgment process. The discussion draws on experiences gathered through studies of nuclear reactor safety and hazardous waste disposal as well as the literature dealing with the encoding of subjective probability distributions