On the track of the expert

The collective risk situations put the settings of expertise to the test. In this paper, we study the activity of the french interministerial committee called for answering the problems caused by the bovine spongiform encephalopathy. The analyse of the activity of expertise is focused on the rules and the procedures mobilized by the experts to produce their advices, without separating their production from the framewok of justification of the governmental action. We show how this committee formed a collective producer of documents in order to leave traces of the way he carries out his mission, and particularly his relationships with his administrative supervision through a game of written questions and answers. [Copyright &y& Elsevier]