Qualitative reasoning under uncertainty

In this paper, we focus our attention on the processing of the uncertainty encountered in the natural langusge. Firstly, we explore the uncertainty concept and then we suggest a new approach which enables a representa-tion of the uncertainty by using linguistic values. The originality of our approach is that it allows to reason on the symbolic uncertainty interval ~Certain, Totally uncertain]. The uncertainty scale that we use here, presents some advantages over other scales in the rep-resentation and in the management of the uncertainty. The axiomatic of our approach is inspired by the Shan-non theory of entropy and built on the substrate of a symbolic many-~-alued logic. So, the uncertainty man-agement in the symbolic logic framework leads to gen-eralizations of classical inferences rules