title: Curating the Specificity of Metadata while World Models Evolve
creators: Yannis Tzitzikas Anastasia Analyti Mary Kampouraki
abstract: The main digital preservation strategies are based on metadata
  and in many cases SemanticWeb languages, like RDF/S, are used for expressing them. However RDF/S schemas or ontologies are not static, but evolve. This evolution usually happens independently of the “metadata” (ontological instance descriptions) which are stored in the various Metadata Repositories (MRs) or Knowledge Bases (KBs). Nevertheless,
  it is a common practice for a MR/KB to periodically update its ontologies to their latest versions by “migrating” the available instance descriptions to the latest ontology versions. Such migrations incur gaps regarding the specificity of the migrated metadata, i.e. inability to distinguish those descriptions that should be reexamined (for possible specialization as consequence of the migration) from those for which no reexamination is justified. Consequently, there is a need for principles, techniques, and tools for managing the uncertainty incurred by such migrations, specifically techniques for (a) identifying automatically the descriptions that are candidate for specialization, (b) computing, ranking and recommending possible specializations, and (c) flexible interactive techniques for updating the available descriptions (and their candidate specializations), after the user (curator of the repository) accepts/rejects such recommendations. This problem is especially important for curated knowledge bases which have increased quality requirements (as in e-Science). In this paper we elaborate on this problem, we propose a general approach, and discuss examples and a prototype application that we have developed assuming the RFD/S framework.
keywords: ischool toronto canada digital preservation metadata metadata repositories migrations