Résumé
This paper proposes an approach to representing preferences about multifactorial ratings. Instead of defining a scale of values and aggregation operations, we propose to express rationality conditions and other generic properties, as well as preferences between specific instances, by means of constraints restricting a complete pre-ordering among tuples of values. The derivation of a single complete pre-order is based on possibility theory, using the minimal specificity principle. Some hints for revising a given preference ordering when new constraints are required, are given. This approach looks powerful enough to capture many aggregation modes, even some violating co-monotonic independence.