Trying to characterize the procedures used in Multi-Criteria Decision Aid

This paper is an attempt at a defense and, to some modest extent, an illustration of the potential role of theoretical results and axiomatization in Multi-Criteria Decision Aid. The paper recalls the different approaches to multi-criteria decision (descriptive, normative and constructive) which have been extensively discussed in the literature and it argues that, even in the constructive approach, theoretical results can help to conceive better procedures and can offer guidelines for selecting procedures which are adequate to particular decisional situations. in any case, the paper disagrees with a normative use of axioms in a decision aid process.