creators_name: Schonfeld, Uri creators_name: Shivakumar, Narayanan type: conference_item datestamp: 2009-04-06 19:11:37 lastmod: 2009-04-24 08:38:59 metadata_visibility: show title: Sitemaps: Above and Beyond the Crawl of Duty ispublished: pub full_text_status: public pres_type: paper abstract: Comprehensive coverage of the public web is crucial to web search engines. Search engines use crawlers to retrieve pages and then discover new ones by extracting the pages’ outgoing links. However, the set of pages reachable from the publicly linked web is estimated to be significantly smaller than the invisible web [5], the set of documents that have no incoming links and can only be retrieved through web applications and web forms. The Sitemaps protocol is a fast-growing web protocol supported jointly by major search engines to help content creators and search engines unlock this hidden data by making it available to search engines. In this paper, we perform a detailed study of how “classic” discovery crawling compares with Sitemaps, in key measures such as coverage and freshness over key representative websites as well as over billions of URLs seen at Google. We observe that Sitemaps and discovery crawling complement each other very well, and offer different tradeoffs. Categories and Subject Descriptors: H.3.3: Information Search and Retrieval. General Terms: Experimentation, Algorithms. Keywords: search engines, crawling, sitemaps, metrics, quality. date: 2009-04 pagerange: 991-991 event_title: 18th International World Wide Web Conference event_location: Madrid, Spain event_dates: April 20th-24th, 2009 event_type: conference refereed: TRUE citation: Schonfeld, Uri and Shivakumar, Narayanan (2009) Sitemaps: Above and Beyond the Crawl of Duty. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain. document_url: http://www2009.eprints.org/100/1/p991.pdf document_url: http://www2009.eprints.org/100/2/WWW2009_Presentation_final_sharable.ppt