Within the framework of the implementation of new European regulations about protection of the geographical denominations of food products, the French interpretation needs a new kind of scientific valuation upon the justification of exclusive use of the geographical name. This work of scientific valuation takes place into an institutional decision-making process, concretised by ediction of standards. The competencies of the scientist are thus mobilised but what is the nature of this work ? Does the scientist produce new scientific knowledge and/or becomes a producer of standards ? We treat of these questions into valuation on requests of registration for Protected Geographical Indications we have been in charge with. During the critical analysis of the justification of the link between the product and its geographical origin, the scientist is testing both the validity of the request and the legitimacy of the applicants. He understands the mission of scientific valuation as a work of mediation between public authorities and local actors, as well as within each one of these institutions. The mediations relate to explicitation of the arguments and criteria of their admissibility, and emphasise on the setting of connection between the actors and between their registers. This new area of deliberation opens up a possible agreement. Such geographical qualifications lead to design the territory not only as a space of validation of the regulations, but also as the place of constitution and collective appropriation of local knowledge. The evaluation of arguments in terms of coherence and relevance seems to be a durable need for institutional decision-making procedures.