Ontology extraction from tables on the Web

Previous works on information extraction from tables make use of prior knowledge such as a cognition model of tables or lexical knowledge bases for specific domains. However, we often need to interpret table structures in each table differently and to treat lexicons in various domains to more fully utilize the broad range of tables available on the Web. The method proposed in this paper uses relations represented by structures to extract an ontology from a table. Once the interpretations of table structures are given by humans, the table structures are automatically generalized to extract relations from the whole table. We define a formal representation of generalized table structure based on the adjacency of cells and iterative structures. As the result of the comparison with a method proposed in a previous work, it was shown that our method is suited to extraction of various relations which are needed for descriptions in RDF/OWL.