This invention aims to provide an efficient means of performing a document
search wherein relevance between plural document databases is examined. A
summary making module and a search module are provided to document
databases, and these are connected to a network as a server. A client
obtains a relevant set of documents in a specified document database via
this summary from a set of documents in the specified document database.
The summary obtained is sent to another server, and a search is performed
according to the summary in a document database in the server to which
the summary is transferred.