Stephen Robertson was given the Salton award by ACM SIGIR in 2000.
The award is given every three years for research in information retrieval. It is named for the first holder, Gerard Salton; the intervening winners have been Karen Sparck Jones, Cyril Cleverdon, William Cooper and Tefko Saracevic.
Stephen's citation reads "...for thirty years of significant, sustained and continuing contributions to research in information retrieval. Of special importance are the theoretical and empirical contributions to the development, refinement and evaluationof probabilistic models of information retrieval.".