Towards Disambiguating Web Tables

Web tables comprise a rich source of factual information. However, without semantic annotation of the tables' content the information is not usable for automatic integration and search. We propose a methodology to annotate table headers with semantic type information based on the content of column's cells. In our experiments on 50 tables we achieved an F1 value of 0.55, where the accuracy greatly varies depending on the used ontology. Moreover, we found that for 94% of maximal F1 score only 20 cells (37%) need to be considered on average. Results suggest that for table disambiguation the choice of the ontology needs to be considered and the data input size can be reduced.