What is Document Keyphrases

Document keyphrases provide semantic metadata which can characterize documents and produce an overview of the content of a document. This chapter describes a Keyphrase Identification Program (KIP), which extracts document keyphrases by using prior positive samples of human identified domain keyphrases to assign weights to the candidate keyphrases. The logic of our algorithm is: the more keywords a candidate keyphrase contains and the more significant these keywords are, the more likely this candidate phrase is a keyphrase. To obtain human identified positive inputs, KIP first populates its glossary database using manually identified keyphrases and keywords. It then checks the composition of all noun phrases extracted from a document, looks up the database and calculates scores for all these noun phrases. The ones having higher scores will be extracted as keyphrases. KIP’s learning function can enrich the glossary database by automatically adding new identified keyphrases to the database.