Analysis of Document Structures for Element Type Classification

As more and more digital documents become available for the public use from diierent sources, also the needs of the users increase. Seamless integration of heterogenous collections, e.g., a possibility to query and format documents in a uniform way, is one of these needs. Processing of documents is greatly enhanced if the structure of documents is explicitly represented by some standard (SGML, XML, HTML). Hence, the problem of integrating heterogenous structures has to be taken into consideration. We address this problem by introducing a classiication method that acquires knowledge from document instances and their document type deenitions, and uses this knowledge to attach a generic class to each SGML element type. The classiication retains the tree hierarchy of elements. Although the structure is simpliied, enough distinctions remain to facilitate versatile further processing, e.g., formatting. The class of an element type can be stored in the document type deenition and, using the architectural form feature of SGML, the documents can be processed as virtual documents obeying a pre-deened generic DTD. The speciic usages of the classiication, in addition to formatting and querying, include assembly of new documents from existing document fragments and automatic generation of style sheet templates for original document type deenitions. We have implemented the classiication method and experimented with several document types.