KEYNET is a graph-oriented method for document indexing and
retrieval. Documents must be annotated with small semantic
networks that represent their key concepts. A larger semantic
network (part of a subject-specific ontology) determines which
node and link types (basic concepts and relations) are
considered pertinent to a subject during document retrieval. The
query graph actually used for retrieval may substitute more
general or specific concepts for those specified by the user.
Retrieval does not match large components of the query graph
against whole keynets of documents. Instead, the query graph is
fragmented into small probes of bounded size. These fragments
are matched against document keynets, and resulting retrieval
sets of potentially relevant documents are combined using
fragment-oriented weights. The graph representations, their
fragmentation, and post-retrieval merging of document sets
associated with distinct fragments naturally introduce a
"fuzziness" appropriate to information retrieval notion