Calyampudi Rao was renowned for his many significant advances in statistics, which have important applications in fields as diverse as economics, genetics, geology and biometry. He was particularly well known for the Cramér–Rao bound and the Rao–Blackwell theorem relating to estimators — functions of observed data that estimate the actual value of a quantity of interest.
Using Calyampudi's results, researchers and analysts can not only calculate an estimate, but also how statistically ‘good’ it is. Calyampudi's other contributions ranged from results in multivariate analysis — where data is used to generate results relating to more than one outcome variable at a time — to orthogonal arrays used in design experiments and in industrial quality control.
The great impact of Calyampudi’s work, which also includes a number of textbooks, was reflected in his many accolades. These included the Padma Vibhushan and the India Science Award — the highest scientific award presented by government of India — in 2010, the Royal Statistical Society’s Guy Medal in Gold, and the US President’s National Medal of Science.
Professor Calyampudi Rao FRS died on 22 August 2023.