We should also know that Nokia Corporation refers to the same company, and that there is a town called Nokia in Finland, to ensure that we make the right classification of the word. Some of this metadata of metadata is general and branch-independent, while some is specific to a branch or topic. Our application and our metadata DTD treat all the found proper nouns similarly, so that there is no system-supported function to help decide the most significant proper nouns in the article. This kind of information could easily be accumulated automatically, and stored in the metadata document. Our metadata documents are fairly large since also excerpts from the article, such as the headnote and the subtitles, are included in the metadata.
Some information is stored twice.
With future tools and databases for XML documents we can expect to minimize such redundancy. There is some redundancy also in the sense that the content describing proper nouns are tagged in the document and included in the metadata. The classifications of proper names and stories allow to know a lot of the content of the article and to make precise searches. But very detailed classifications are not always practical for the persons who make queries into the database, because they should know the classification principles as well as those who make the classifications. This should be considered very carefully, when classification schemes and user interfaces for queries are made.