http://www2009.eprints.org/2/ Click Chain Model in Web Search Guo, Fan Liu, Chao Kannan, Anitha Minka, Tom Taylor, Michael Wang, Yi-Min Faloutsos, Christos Given a terabyte click log, can we build an efficient and effective click model? It is commonly believed that web search click logs are a gold mine for search business, because they reflect users’ preference over web documents presented by the search engine. Click models provide a principled approach to inferring user-perceived relevance of web documents, which can be leveraged in numerous applications in search businesses. Due to the huge volume of click data, scalability is a must. We present the click chain model (CCM), which is based on a solid, Bayesian framework. It is both scalable and incremental, perfectly meeting the computational challenges imposed by the voluminous click logs that constantly grow. We conduct an extensive experimental study on a data set containing 8.8 million query sessions obtained in July 2008 from a commercial search engine. CCM consistently outperforms two state-of-the-art competitors in a number of metrics, with over 9.7% better log-likelihood, over 6.2% better click perplexity and much more robust (up to 30%) prediction of the first and the last clicked position. 2009-04 Conference or Workshop Item PeerReviewed application/pdf http://www2009.eprints.org/2/1/p11.pdf application/vnd.ms-powerpoint http://www2009.eprints.org/2/2/www09_ccm.ppt Guo, Fan <http://www2009.eprints.org/view/author/Guo=3AFan=3A=3A.html> and Liu, Chao <http://www2009.eprints.org/view/author/Liu=3AChao=3A=3A.html> and Kannan, Anitha <http://www2009.eprints.org/view/author/Kannan=3AAnitha=3A=3A.html> and Minka, Tom <http://www2009.eprints.org/view/author/Minka=3ATom=3A=3A.html> and Taylor, Michael <http://www2009.eprints.org/view/author/Taylor=3AMichael=3A=3A.html> and Wang, Yi-Min <http://www2009.eprints.org/view/author/Wang=3AYi-Min=3A=3A.html> and Faloutsos, Christos <http://www2009.eprints.org/view/author/Faloutsos=3AChristos=3A=3A.html> (2009) Click Chain Model in Web Search. In: 18th International World Wide Web Conference, April 20th-24th, 2009, Madrid, Spain. http://www2009.eprints.org/2/http://www2009.eprints.org/2/1/http://www2009.eprints.org/2/2/