Extending a Description Logic to Cope with the Completeness
of Multimedia Documents.
In Proceedings of ECAI96 Workshop on Knowledge Representation
for Interactive Multimedia Systems, pages 42--50, Budapest, Hungary, 1996.
Logic is a suitable tool for modelling the retrieval of multimedia documents, as
it offers a well founded and universally accepted framework for representing documents
and user requests, while viewing retrieval as inference. Especially the latter feature
is of extreme interest to information retrieval, as it allows, among other things,
to make proper usage of the many kinds of knowledge involved in this task. However,
logic as it is also suffers from several drawbacks that make it too rigid to cope
with real domains. We address one of these problems, by defining a logic for the
retrieval of multimedia documents allowing the expression and proper handling of
closure assertions. A closure assertion is meta-knowledge about the completeness
of the knowledge on a specified individual or predicate symbol.