creators_name: Abdel Hamid, Ossama creators_name: Behzadi, Behshad creators_name: Christoph, Stefan creators_name: Henzinger, Monika type: conference_item datestamp: 2009-04-06 19:08:41 lastmod: 2009-04-14 04:37:05 metadata_visibility: show title: Detecting the Origin of Text Segments Efficiently ispublished: pub full_text_status: public pres_type: paper abstract: In the origin detection problem an algorithm is given a set S of documents, ordered by creation time, and a query document D. It needs to output for every consecutive sequence of k alphanumeric terms in D the earliest document in S in which the sequence appeared (if such a document exists). Algorithms for the origin detection problem can, for example, be used to detect the “origin” of text segments in D and thus to detect novel content in D. They can also find the document from which the author of D has copied the most (or show that D is mostly original.) We propose novel algorithms for this problem and evaluate them together with a large number of previously published algorithms. Our results show that (1) detecting the origin of text segments efficiently can be done with very high accuracy even when the space used is less than 1% of the size of the documents in S , (2) the precision degrades smoothly with the amount of available space, (3) various estimation techniques can be used to increase the performance of the algorithms. date: 2009-04 pagerange: 61-61 event_title: 18th International World Wide Web Conference event_location: Madrid, Spain event_dates: April 20th-24th, 2009 event_type: conference refereed: TRUE citation: Abdel Hamid, Ossama and Behzadi, Behshad and Christoph, Stefan and Henzinger, Monika (2009) Detecting the Origin of Text Segments Efficiently. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain. document_url: http://www2009.eprints.org/7/1/p61.pdf