Experiments on Patent Retrieval at NTCIR-4 Workshop
Hironori Takeuchi, Naohiko Uramoto, Koichi Takeda · 2004
the search topic was the claim in a patent document and the search re-sults were the patents that invalidate the claim in the query. Therefore we can calculate the similarities be-tween the IPCs in the search topic and those of each patent document in the collection and use them for the patent-to-patent search. In this task, we extracted the relevance infor-mation from the search results based on the similarities between hierarchi-cal structures of the IPCs, modified the term weighting in the query pro-cessing, and got the final retrieved documents using the updated query. As a result, it was found that there are no significant improvements from term re-weighting when considering the relevance information from the search results using hierarchical in-formation of IPCs. Keywords:similarity metric, hierar-chical structural information, rele-vance feedback, patent retrieval 1