Katur — also written Katoor — is a small village in the Buchinaidu Kandriga area of Chittoor district, in the south of Andhra Pradesh. It was there, on 13 June 1937, in what was then the Madras Presidency of British India, that Dabbala Rajagopal Reddy was born. The village had no electricity to speak of and no tradition of higher study, and he was the first member of his family to attend school beyond the elementary level. He would go on to become one of the founding figures of artificial intelligence, and to spend much of his later life trying to give children in villages like his own the access to knowledge that he had very nearly not had.

From Chittoor to Stanford

Reddy's early schooling was local and unremarkable in every respect except that it continued. He went on to the College of Engineering at Guindy in Madras — one of the oldest engineering institutions in Asia — and took a bachelor's degree in civil engineering. Computing was not then a subject one could study in India, and his route into it was oblique. He worked for a period with the Applied Science division of IBM in Australia in the early 1960s, an experience that put him in front of machines at exactly the moment when the question of what they might be made to do was becoming interesting. He completed a master's degree in technology at the University of New South Wales in 1960.

In 1963 he moved to Stanford University for doctoral work, and in 1966 he received what was among the first doctorates in computer science awarded there. His supervisor was John McCarthy, who had coined the term "artificial intelligence" a decade earlier and who was then assembling the field almost from first principles. Reddy's thesis addressed the recognition of connected speech — not isolated words spoken carefully into a microphone, but continuous human speech, with its slurred boundaries, its variable speed and its dependence on context. It was an audacious problem for the hardware of the 1960s, and it set the direction of the next forty years of his work.

Carnegie Mellon and the speech systems

He stayed at Stanford as an assistant professor from 1966, and in 1969 he moved to Carnegie Mellon University in Pittsburgh, where he spent the remainder of his career. He became a full professor in 1973 and a University Professor in 1984.

The systems his groups built at Carnegie Mellon are landmarks in the history of the field. Hearsay-I, and then the more influential Hearsay-II, tackled continuous speech understanding by having many specialised knowledge sources — acoustic, phonetic, lexical, syntactic, semantic — contribute hypotheses to a shared working structure, each refining and constraining the others. The architecture, known as the blackboard model, was subsequently adopted well beyond speech research and remains one of the most widely cited contributions to the design of complex reasoning systems. Alongside it his groups produced Harpy, which introduced an efficient search strategy over a network of possible utterances and achieved the best recognition performance of its generation, and Dragon, which pioneered the statistical treatment of speech that later became standard. The Sphinx systems, developed under his direction in the 1980s, were the first to demonstrate speaker-independent, large-vocabulary continuous speech recognition — the technology that eventually reached ordinary telephones and household devices.

Reddy's institutional work matched his research. In 1979 he founded the Robotics Institute at Carnegie Mellon and served as its director until 1991; it grew into the largest university robotics establishment in the world. From 1991 to 1999 he was dean of the university's School of Computer Science, presiding over its expansion during the years in which computing moved from a specialist discipline to a central one.

The Turing Award and other honours

In 1994 he received the A. M. Turing Award, the highest distinction in computer science, jointly with Edward Feigenbaum, for pioneering the design and construction of large-scale artificial intelligence systems and for demonstrating the practical importance and commercial potential of the technology. He was the first person of Asian origin to receive the award. The citation captured something particular about his approach: he was less interested in artificial intelligence as a philosophical question than in building systems large and robust enough to be genuinely useful.

Other recognition followed over the decades. France made him a chevalier of the Legion of Honour in 1984. He received the Padma Bhushan from the Government of India in 2001, the Okawa Prize in 2004, the Honda Prize in 2005, and the Vannevar Bush Award in 2006. He served as president of the American Association for Artificial Intelligence, and he co-chaired the President's Information Technology Advisory Committee in the United States, which shaped federal research priorities for computing at the turn of the century.

Bringing technology home

What distinguishes Reddy from many of his contemporaries is the sustained attention he has given to India, and particularly to students from circumstances resembling his own. He was a founding figure behind the International Institute of Information Technology at Hyderabad and chaired its governing council. He co-founded the Million Book Project, an effort begun in 2001 to digitise a million books and make them freely readable, with substantial scanning work carried out in India and China — an early argument that the world's written record should not be locked behind distance or cost.

His most direct intervention came with the Rajiv Gandhi University of Knowledge Technologies in Andhra Pradesh, of which he was founding chancellor from 2008. RGUKT was designed specifically to admit talented students from rural government schools who would otherwise be excluded from competitive engineering education, and to teach them with technology-assisted methods. It is an idea traceable in a straight line to Katur: the recognition that ability is distributed evenly across villages and cities, and that opportunity is not.

Legacy

Raj Reddy's name is attached to the machinery of everyday life in a way few researchers achieve. Every system that transcribes a spoken sentence, answers a spoken question or reads a spoken command descends, through many intermediate generations, from work he began when the idea that a machine might understand continuous speech was regarded as improbable. For a village in Chittoor district, his life offers a plain and remarkable fact: a boy who had to walk to school became one of the people who taught machines to listen.