As the recipient of the 2009 ACM-Infosys Foundation Award, Kleinberg was cited for his work on the use of link analysis, a search technique that ranks the absolute number as well as the most relevant, trusted sources of pages linked to a Web search query. His Hubs and Authorities algorithm along with Google’s PageRank algorithm appeared at a time when Web search techniques were based on keyword indexing. Together, this work revealed a basic relationship between network structure and information that fundamentally changed the direction of research and commercial activity on the Web.