Applying key phrase extraction to aid invalidity search

Invalidity search poses different challenges when compared to conventional Information Retrieval problems. Presently, the success of invalidity search relies on the queries created from a patent application by the patent examiner. Since a lot of time is spent in constructing relevant queries, automatically creating them from a patent would save the examiner a lot of effort. In this paper, we address the problem of automatically creating queries from an input patent. An optimal query can be formed by extracting important keywords or phrases from a patent by using Key Phrase Extraction (KPE) techniques. Several KPE algorithms have been proposed in the literature but their performance on query construction for patents has not yet been explored. We systematically evaluate and analyze the performance of queries created by using state-of-the-art KPE techniques for invalidity search task. Our experiments show that queries formed by KPE approaches perform better than those formed by selecting phrases based on tf or tf-idf scores.