Controlled Migration in Digital Archives

Since quite a while, long term preservation of digital information has become a challenging issue. Migration and emulation are two approaches that have been suggested for making today's knowledge available for future generations. Although migration, in particular, is progressively being used in digital archiving, there is still a lack of formalization. In planning and running comprehensive migration processes, librarians and archivists face the major challenge of preserving the original information. To reduce unrecognized information change or information loss, it would be useful to have a formal framework allowing to qualitatively specify information. Quantitative and probabilistic approaches lack the possibility to discover when which information changes or is lost. In this paper, we propose how to capture the notion of information and to qualify information loss during migration processes. Furthermore, we use the Unified Modeling Language (UML) to exemplary design an information structure and illustrate some major problems that arise when a migration is planned and executed.