Hierarchies in HTML documents: linking text to concepts

For the successful setting of the semantic Web, it is necessary to provide tools for linking the large amounts of data that are currently available in HTML documents to the semantic Web ontologies. Due to the enormous variability of the HTML code, it is very limiting to define direct bindings between patterns of the HTML code and the concepts. We propose an approach based on modeling the visual part of the rendered document and describing the key characteristics of the data presentation in a general way. As a next step, we propose the way for using this model for locating the instances of the concepts in the document using the approximate tree matching algorithms and regular expressions.