Communication à un séminaire :
Aggregation of information provided by experts is usually conceived as independent from the decision maker's preferences. We argue that this entails a substantial loss, insofar as it precludes the possibility to take into account simultaneously the decision maker's attitude towards disensus among experts and her attitude towards imprecision of information. We propose to consider directly how a decision maker behaves when using information coming from several sources. We give an axiomatic foundation for a decision criterion that allows to distinguish on a behavioral basis the decision maker's attitude towards imprecision and towards disensus.