Abstract  Our previous work on specialized digital libraries showed that each expert was brought to enrich the documentary corpus with his/her point of view (expressed by a model of knowledge). These points of view can be contradictory and therefore, it would be interesting to provide expert communities with tools, enabling them to point out meaning dissensions. In Archaeology, the comparison between different temporal models of knowledge make possible the publication of relative models of knowledge. These different models tend towards the emerging of a global knowledge shared by a community. In this paper we present a method and a set of concrete relations proposed to the annotator, which allows to extend some existing models of knowledge and to build new temporal knowledge. The proposed model, based on temporal algebra relations, permits the use of some efficient constraint propagation algorithms to extract new information.