Formal Models for Digital Archives: NESTOR and the 5S

Abstract. Archives are a valuable part of our cultural heritage but despite their importance, the models and technologies that have been developed over the past two decades in the Digital Library (DL) field have not been specifically tailored to them. This is especially true when it comes to formal and foundational frameworks, as the Streams, Struc-tures, Spaces, Scenarios, Societies (5S) model is. Therefore, we propose an innovative formal model, called NEsted SeTs for Object hieRarchies (NESTOR), for archives, explicitly built around the concepts of context and hierarchy which play a central role in the archival realm. We then use NESTOR to extend the 5S model offering the possibility of opening up the full wealth of DL methods to archives. We provide account for this by presenting two concrete applications.