• 1953
    (b.) - ?


A Distinguished Scientist at Google, he has been involved in a wide-range of research activities related to the web and information retrieval, including the famous "bow-tie" study of web size and connectivity, and the web archaeology project. He was previously a Research Fellow and Vice President of Computational Advertising for Yahoo!. Prior to Yahoo he worked for AltaVista as The Vice President of Research; and for IBM Research as a Distinguished Engineer and CTO of IBM's Institute for Search and Text Analysis. Born in Bucharest, Romania, his parents were medical doctors - his father was a noted oncological surgeon. The family emigrated to Israel in 1973, when he was in the second year of college in Romania, in the Electronics department at the Bucharest Polytechnic. He was accepted at Technion ? Israel Institute of Technology, in the EE Department. He graduated with a B.Sc. degree - summa cum laude from Technion in 1977. He was then admitted to the Ph.D. program at Stanford University in California, where he initially planned to work in the systems area. His first adviser was Prof. John L. Hennessy. After receiving a "high pass" at the reputedly hard algorithms qual, Prof. Donald Knuth, already a Turing Award and National Medal winner, offered him the rare opportunity to become his advisee. He finished his Ph.D. under Don Knuth in 1984. He then joined the newly founded DEC Systems Research Center in Palo Alto, California. At DEC SRC, he was involved with AltaVista from the very beginning, helping it deal with duplicate documents and spam. When AltaVista split from Compaq which had bought DEC, he became its Chief Technical Officer and then Chief Scientist and Vice President of Research. In 2002, he joined IBM Research in New York to build its enterprise search product. In 2005, he returned to Silicon Valley and the Web Industry, as a Yahoo Fellow and Vice President. There, he put the bases of a new discipline, Computational advertising; the science of matching ads to users and contexts. At Yahoo, he also helped build Yahoo! Research into one of the leading Web research organizations. In 2012, he joined Google as a Distinguished Scientist, where he switched focus to another aspect of the World Wide Web (WWW) experience, large-scale personalization. Over the last fifteen years, he pioneered several algorithms systems and concepts fundamental to the science and technology of the WWW. Some of the highlights are as follows: In 1997, he led the development of the first practical solution for finding near-duplicate documents on web-scale using "shingling" to reduce the problem to a set-intersection problem and "min-hashing" or to construct "sketches" of sets. This was a pioneering effort in the area of locally sensitive hashing, for which he eventually received the 2012 ACM Paris Kanellakis Award. In 1998, he co-invented the first practical test to prevent robots from masquerading as human and access web sites, often referred to as CAPTCHA. In 2000, he, while at AltaVista, together with colleagues from IBM and DEC SRC, conducted the first large-scale analysis of the Web graph, and identified the bow-tie model of the web graph. Around 2001-2002, he published an opinion piece where he qualified the differences between classical information retrieval and Web search; and introduced a now-widely-accepted classification of web queries into navigational, information, and transactional. He is a fellow of ACM and IEEE.
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    Co-inventor of the first practical test to prevent robots from masquerading as human and access web sites - often referred to as CAPTCHA
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