Raj Reddy pioneered the construction of systems for recognizing continuous speech. He developed the first system, Hearsay I, capable of continuous speech recognition. In this system and subsequent systems like Hearsay II, Harpy, and Dragon, he and his students developed most of the ideas underlying modern commercial speech recognition technology. Some of these ideas—most notably the “blackboard model” for coordinating multiple knowledge sources—have been adopted across the spectrum of applied artificial intelligence. Together, the joint Turing Award recipients in 1994, Edward Feigenbaum and Raj Reddy, have been seminal leaders in defining the emerging field of applied artificial intelligence and demonstrating its technological significance.

Raj Reddy is renowned for his work in computer speech recognition, robotics, human-computer interaction, innovations in higher education, and efforts to bring digital technology to people on the other side of the “digital divide.”

Dabbala Rajagopal (Raj) Reddy was born on June 13, 1937 in Katoor, Andhra Pradesh, India. His father, Srdenivasulu Reddy, was an agricultural landlord and his mother, Pitchamma, was a homemaker. Reddy attended the ZP High School at Sri Kalahasti in Chittoor District, and received his Bachelor’s degree in civil engineering from Guindy College of Engineering, Madras (now Anna University, Chennai), India, in 1958. As an ROTC student in India he learned to fly, and later said that he used to fly bi-planes and do aerobatics. After his undergraduate work, he moved to Australia as an exchange student and received a Master’s degree in technology in 1960 from the University of New South Wales in Sydney, Australia. Upon finishing his Master’s, he worked as an Applied Science Representative for IBM in Australia.

In 1963, Reddy came to Stanford University as a PhD student. In early 1964, he began a class project under John McCarthy (himself a Turing Award recipient) on speech recognition, employing the Stanford AI Lab’s newly acquired analog-to-digital converter and PDP-1 computer to process speech waveforms. In a later interview, Reddy said that he chose that project, among several others suggested by McCarthy, because he was interested in natural languages and what could be learned about them using computers. Little did he know that his “class project” would occupy a lifetime. Reddy completed his PhD dissertation in 1966 under the supervision of McCarthy, on speech recognition. It was the first PhD granted by Stanford’s newly-formed Department of Computer Science.

Reddy stayed at Stanford as an assistant professor, doing and directing work on speech recognition, image processing, and face recognition. In 1969, attracted by Allen Newell, Herbert Simon and Alan Perlis (all three are also Turing Award recipients), he accepted a position as an associate professor at Carnegie Mellon University, where he continued his research on speech recognition and image processing. He became a Full Professor in 1973, and a University Professor in 1984. He served as the founding Director of the Robotics Institute from 1980 to 1992 and as the Dean of the School of Computer Science from 1991 to 1999. He became the Founding Director of Carnegie Mellon’s West Coast Campus in 2001, serving in that position until 2004.

In 1970, not long after Reddy arrived at CMU, Allen Newell chaired a committee sponsored by DARPA, the Defense Advanced Research Projects Agency, to investigate the feasibility of beginning a large-scale, five-year, community-wide project on “speech understanding.” CMU was among the groups funded to carry out research outlined by the committee, and Reddy headed the project. Even though CMU made notable achievements during that time, fielding successful speech-understanding systems called HEARSAY II, HARPY, and DRAGON, DARPA decided not to renew the main projects as such, but it did continue to support Reddy’s work on speech understanding at a reduced level at CMU under its basic research program.

Over a span of three decades, Reddy and his colleagues created several historic demonstrations of spoken language systems, such as voice control of robots, large-vocabulary connected speech recognition, speaker independent speech recognition, and unrestricted vocabulary dictation. They developed many of the ideas that underlie modern commercial speech recognition products.

Reddy and his colleagues have also made seminal contributions to other areas of artificial intelligence and computer science, notably to task-oriented architectures, analysis of natural scenes, and autonomous robotic systems. The “blackboard architecture” for coordinating multiple knowledge sources, developed under CMU’s speech understanding research program, has been widely adopted.

From about 1975 on, Reddy’s research interests expanded in several directions. He was one of the major collaborators at CMU with DARPA, and was instrumental in getting DARPA work started on VLSI research, sensor networks, operating systems (the “MACH” system, which is the foundation of Apple’s MAC OSX), and user interfaces and workstations. He also experimented with graphics printing.

In 1978 and 1979 Reddy persuaded the Westinghouse Corporation and others to support the newly-created Robotics Institute at CMU. He served as its founding director from 1979 to 1991. Reddy was able to persuade several gifted scientists to join. The Institute carries on research in several robotics-related fields, including space robotics, computer graphics, medical robotics, computer vision, and artificial intelligence. It played, and still plays, a leading role in making Pittsburgh a center for robotics research and applications. Its headquarters building is sometimes affectionately called the “Raj Mahal” in honor of its founder.

Computer science at CMU gradually outgrew in scope and size what could be housed in one department. In 1988, it became the School of Computer Science, and Reddy served as Dean from 1991 to 1999. In that position he helped create the Language Technologies Institute, the Human Computer Interaction Institute, the Center for Automated Learning and Discovery (since renamed the Department of Machine Learning), and the Institute for Software Research.

In 2005, Reddy was honored as the first recipient of the Mozah Bint Nasser Chair of Computer Science and Robotics. A gift from the Qatar Foundation, the chair was awarded as part of the inaugural celebration honoring the opening of CMU’s new campus in Qatar.

Reddy continues to innovate technically, organizationally, and as a computer science spokesperson. He was one of the founders of the American Association for Artificial Intelligence (now called the Association for the Advancement of Artificial Intelligence) and was its President from 1987 to 1989. He was a co-chair of the President's Information Technology Advisory Committee (PITAC) from 1999 to 2001. He serves on the International Board of Governors of the Peres Center for Peace based in Israel.

He actively participates in a number of organizations in India. He is a member of the governing board of the GVK Emergency Management and Research Institute, and of the Indian Institute of Health Management. He is the chairman of the Governing Council of the International Institute of Information Technology, Hyderabad, where Reddy and colleagues have developed Indian language processing. He helped found and is the Chancellor and the Chairman of the Governing Council of the Rajiv Gandhi University of Knowledge Technologies, which caters to the educational needs of gifted rural youth. In 2001, Reddy was awarded the Padma Bhushan, the third-highest civilian award given by the Indian Government, for distinguished service of a high order to the nation.

Reddy has participated in many other organizing activities. Among them are his role in getting a Silicon Valley branch of CMU started, and his involvement in the Universal Digital Library Project, whose goal is to coordinate all the world’s knowledge on the Web. “All of my projects are interrelated,” he told one interviewer, “In order to solve any one of them, you have to solve all of them.”

Reddy is extraordinarily talented at persuading people to help with his projects. Jim Morris, a former Dean of CMU’s School of Computer Science, mentioned that one of Reddy’s most effective tools of persuasion is something called the “full Raj” embrace—not to be confused with the mere “half Raj,” a tactic used for less critical tasks. Morris defined a “half Raj” as just an arm on your shoulder; a “full Raj” brings you into his neck.

Reddy’s accomplishments have led to many awards and honors. In addition to being a co-recipient with Ed Feigenbaum of the ACM Turing Award in 1994, he is a member of the National Academy of Engineering and the American Academy of Arts and Sciences. He was awarded the Legion d’Honneur, by French President Francois Mitterrand in 1984 for his work in developing countries; the Okawa Prize in 2004 for “pioneering researches of large scale artificial intelligence system, human-computer interaction… outstanding contributions to information and telecommunications policy”, the Honda Prize in 2005 for his “outstanding achievements in computer science and robotics,” the 2005 IJCAI Donald E. Walker Distinguished Service Award for “his outstanding service to the AI community,” and the Vannevar Bush Award in 2006 for his “pioneering research in robotics and intelligent systems, and his significant contributions in the formulation of national information and telecommunications policy.”

For a 1991 oral history interview of Reddy, see: http://conservancy.umn.edu/bitstream/107605/1/oh231rr.pdf

Author: Nils J. Nilsson