Learning Algorithms for Keyphrase Extraction phrases that match up to 75% of the authors keyphrases There is a need for tools that can automatically create keyphrases. Although keyphrases are very useful, only a small minority of the many documents that are available on-line today have keyphrases. There are already some commercial software products that use automatic keyphrase extraction algorithms. For example, Microsoft uses automatic keyphrase extrac tion in Word 97, to fill the Keywords field in the document metadata template(metadata is meta-information for document management ). Verity uses automatic keyphrase extraction in Search 97, their search engine product line. In Search 97. keyphrases are highlighted in bold to facilitate skimming through a list of search results Tetranet uses automatic key phrase extraction in their Metabot product, which is designed for maintaining metadata for web pages. Tetranet also uses automatic keyphrase extraction in their wisebot product, which builds an index for a web site Although the applications for keyphrases mentioned above share the requirement for a short list of phrases that captures the main topics of the documents, the precise size of the list will vary, depending on the particular application and the inclinations of the users. Therefore he algorithms that we discuss allow the users to specify the desired number of phrases We discuss related work by other researchers in Section 3. The most closely related work involves the problem of automatic index generation(Fagan, 1987; Salton, 1988; Ginsberg, 1993; Nakagawa, 1997; Leung and Kan, 1997). One difference between keyphrase extraction 1. To access the metadata template in Word 97, select File and then Properties. To au field, select Tools and then AutoSummarize. (This is not obvious from the word 97 documentation ) Microsoft and Word 97 are trademarks or registered trademarks of Microsoft Corporation 2. Microsoft and Verity use proprietary techniques for keyphrase extraction. It appears that their techniques do not involve machine learning. Verity and Search 97 are trademarks or registered trademarks of Verity Inc 3. Tetranet has licensed our keyphrase extraction software for use in their products. Tetranet, Metabot, and wise- bot are trademarks or registered trademarks of Tetranet Software. For experimental comparisons of Word 97 and Search 97 with our own work, see Turney (1997, 1999)Learning Algorithms for Keyphrase Extraction 3 phrases that match up to 75% of the author’s keyphrases. There is a need for tools that can automatically create keyphrases. Although keyphrases are very useful, only a small minority of the many documents that are available on-line today have keyphrases. There are already some commercial software products that use automatic keyphrase extraction algorithms. For example, Microsoft uses automatic keyphrase extrac￾tion in Word 97, to fill the Keywords field in the document metadata template (metadata is meta-information for document management).1 Verity uses automatic keyphrase extraction in Search 97, their search engine product line. In Search 97, keyphrases are highlighted in bold to facilitate skimming through a list of search results.2 Tetranet uses automatic key￾phrase extraction in their Metabot product, which is designed for maintaining metadata for web pages. Tetranet also uses automatic keyphrase extraction in their Wisebot product, which builds an index for a web site.3 Although the applications for keyphrases mentioned above share the requirement for a short list of phrases that captures the main topics of the documents, the precise size of the list will vary, depending on the particular application and the inclinations of the users. Therefore the algorithms that we discuss allow the users to specify the desired number of phrases. We discuss related work by other researchers in Section 3. The most closely related work involves the problem of automatic index generation (Fagan, 1987; Salton, 1988; Ginsberg, 1993; Nakagawa, 1997; Leung and Kan, 1997). One difference between keyphrase extraction 1. To access the metadata template in Word 97, select File and then Properties. To automatically fill the Keywords field, select Tools and then AutoSummarize. (This is not obvious from the Word 97 documentation.) Microsoft and Word 97 are trademarks or registered trademarks of Microsoft Corporation. 2. Microsoft and Verity use proprietary techniques for keyphrase extraction. It appears that their techniques do not involve machine learning. Verity and Search 97 are trademarks or registered trademarks of Verity Inc. 3. Tetranet has licensed our keyphrase extraction software for use in their products. Tetranet, Metabot, and Wise￾bot are trademarks or registered trademarks of Tetranet Software. For experimental comparisons of Word 97 and Search 97 with our own work, see Turney (1997, 1999)