The comments made by any individual questioned about his or her working life do not only provide some information about the functioning of the activity in question. They are full of traces of their culture. There is a complementarity between the different forms of expression of actors, their metaphors and their narratives. The transition from a collection of traces to a structured and coherent representation of a culture involves an abduction approach: the traces that are available only take on all their meaning (and even, in certain cases, are only perceived) when one has managed to give them a place within an overall picture and this picture is itself built using these clues. It is a case of a hermeneutic circle. The power of conviction of the result obtained comes from the way in which once they have been collected, a number of characteristics that at first sight appear to be disparate form a figure that gives a feeling of coherence. An essential step is to make an assumption that provides an overall hypothetical interpretation of all the available clues. Much of the quality of the final result depends on the relevance of such an assumption. A second step involves verifying whether all the available clues are consistent with this hypothesis, before making a new assumption if the test is negative.