He is known for his work on probabilistic information retrieval together with Karen Spärck Jones[1] and the Okapi BM25 weighting model.
[2][3] Robertson was born in London, England,[citation needed] to (Theodosia) Cecil, née Spring Rice (1921–1984) and Martin Robertson (1911–2004),[4] an internationally distinguished professor of Classical Greek Art and Archaeology at the University of London, Oxford University, and Trinity College, Cambridge.
His younger brother is composer and musician Thomas Dolby.
Okapi BM25 is very successful in experimental search evaluations and found its way in many information retrieval systems and products, including open source search systems like Lucene, Lemur, Xapian, and Terrier.
He earned his PhD at University College London in 1976 under the renowned statistician and scholar B. C.