Formaliser le raisonnement chronologique et son incertitude en archéologie de terrain

This article is about uncertainty and formalization of the archaeological time. During an archaeological excavation, in order to produce reports and basic chronological information, the archaeologist has to create a first chronological model, with the stratigraphic sequence (Harris matrix), and the available indicators of quantified time (terminus post quem, terminus ante quem). This model may be formalized, particularly the realization of the Harris matrix (graph of stratigraphic chronology). However, at this stage, this model may be affected by uncertainty of stratigraphic observations (because of their empirical nature), and it has to deal with the imprecision of the data of quantified time. From an epistemological point of view, taking this uncertainty into consideration may strengthen the scientific validity of the archaeological reasoning. The formalization exposed below corresponds to this chronological reasoning operated by the archaeologist during archaeological excavations. It gave rise to operational computing tools (application Le Stratifiant). Simple tools of modal logic allow to treat this uncertainty. This formalization takes place upstream to more complex modelling