What should we expect from a multicriteria aggregation procedure for non-cardinal or mixed evaluations?

Very often, in multicriterion analysis, the actions to be compared are eval uated according to a set of conflictual and heterogeneous criteria. Also th ese evaluations can contain elements difficult to quantify. In this case, d ominating informations are often noncardinal or mixed. Several procedures o f multicriterion aggregation (MCAP) are implemented in such a context. After reminding the main difficulties which a MCAP can encounter in such a context and this from the theory of measuring viewpoint, we propose a set o f requirements which should be checked by a MCAP so it can be described as acceptable for such evaluations.