ROB MILNE earned international respect for his innovative work in adapting artificial intelligence (AI) as a practical aid to industry and in bridging the gap between the research laboratory and the factory floor. The company he founded at Livingston near Edinburgh, at the heart of the "Silicon Glen", reversed the initials AI to create Intelligent Applications. The projects and software it produced won many awards for innovation and excellence. Milne's devotion to computer technology was matched by a love of mountains and the physical achievement of reaching the highest summits.

Donald Michie was born in Rangoon on November 11 1923, the son of James Michie and the former Marjorie Crain. From Rugby he won a classical scholarship to Balliol, becoming - according to wartime colleagues - "curator of the Balliol Book of Bawdy Verse". In 1942 he was recruited to Bletchley Park. He was put into Hut F, working to crack the Wehrmacht's "Tunny" machine, which encoded material more sensitive than that carried by the now celebrated "Enigma". The team's success gave the Allies access for the first time to German army situation reports in the run-up to D-Day, with invaluable insights into troop dispositions in France.

Mr Gregory was a pioneer of human psychology, and made significant advances in the fast-changing world of artificial intelligence. Born in London in 1923, he was the son of astronomer Christopher Gregory. Mr Gregory spent five years in the RAF during the Second World War, after being called up at the age of 18. After exhibiting obvious academic talent the RAF offered Mr Gregory a scholarship to study philosophy and experimental psychology at Downing College, Cambridge and after proving himself a successful scientist and inventor he moved to Edinburgh, where he took up a post as professor of bionics. There he co-founded the Department of Machine Intelligence and Perception, the first of its kind in the UK.

"I like to think that since I was about 19, I have studied human decision-making and problem-solving," Dr. Simon said in a Post-Gazette interview last fall. He earned a doctorate in political science at the University of Chicago in 1943 and took teaching positions at the Illinois Institute of Technology and the University of California, Berkeley, before joining the newly established industrial administration school at the Carnegie Institute of Technology.

Dr. Engelbart died on Tuesday at 88 at his home in Atherton, Calif. His wife, Karen O'Leary Engelbart, said the cause was kidney failure. Computing was in its infancy when Dr. Engelbart entered the field. Computers were ungainly room-size calculating machines that could be used by only one person at a time. Someone would feed them information in stacks of punched cards and then wait hours for a printout of answers. Interactive computing was a thing of the future, or in science fiction.

Psychological research was in a kind of rut in 1955 when George A. Miller, a professor at Harvard, delivered a paper titled "The Magical Number Seven, Plus or Minus Two," which helped set off an explosion of new thinking about thinking and opened a new field of research known as cognitive psychology. The dominant form of psychological study at the time, behaviorism, had rejected Freud's theories of "the mind" as too intangible, untestable and vaguely mystical. Its researchers instead studied behavior in laboratories, observing and recording test subjects' responses to carefully administered stimuli. Dr. Miller, who died on July 22 at his home in Plainsboro, N.J., at the age of 92, revolutionized the world of psychology by showing in his paper that the human mind, though invisible, could also be observed and tested in the lab. "George Miller, more than anyone else, deserves credit for the existence of the modern science of mind," the Harvard psychologist and author Steven Pinker said in an interview.

The 3-D research was seminal in the fields of computer vision and artificial intelligence. Known as "constraint propagation," the technique is now used in industry for solving problems like route scheduling, package routing and construction scheduling. At M.I.T., Dr. Waltz was taught by Marvin Minsky, a pioneer in artificial intelligence. Dr. Waltz graduated in 1972, then taught computer science at the University of Illinois at Urbana-Champaign and, later, at Brandeis University in Massachusetts. But it was as a member of a group of researchers at the Thinking Machines Corporation, in Cambridge, Mass., that Dr. Waltz made his breakthrough in information retrieval.

"In the early 1970s, he presented a paper in France on buying and selling by computer, what is now called electronic commerce," said Whitfield Diffie, an Internet security expert who worked as a researcher for Dr. McCarthy at the Stanford Artificial Intelligence Laboratory. And in the study of artificial intelligence, "no one is more influential than John," Mr. Diffie said. While teaching mathematics at Dartmouth in 1956, Dr. McCarthy was the principal organizer of the first Dartmouth Conference on Artificial Intelligence. The idea of simulating human intelligence had been discussed for decades, but the term "artificial intelligence" -- originally used to help raise funds to support the conference -- stuck. In 1958, Dr. McCarthy moved to the Massachusetts Institute of Technology, where, with Marvin Minsky, he founded the Artificial Intelligence Laboratory.

George C. Devol, a largely self-taught inventor who drew from science fiction to help develop Unimate, the revolutionary mechanical arm that became a prototype for robots now widely used on automobile assembly lines and in other industries, died on Thursday at his home in Wilton, Conn. In the early 1950s, before the advent of industrial robotics, Mr. Devol (pronounced de-VAHL) built on his own work in electrical engineering and machine controls to design a mechanical arm that could be programmed to repeat precise tasks, like grasping and lifting. He applied for a patent in 1954 and explained the concept to a fellow engineer, Joseph F. Engelberger, at a cocktail party where they discussed their favorite science fiction writers. Mr. Engelberger listened with interest and immediately seized on the significance of the new technology. Mr. Devol named the concept Universal Automation -- later shortened to Unimation -- and received a patent in 1961.

Joseph Weizenbaum, whose famed conversational computer program, Eliza, foreshadowed the potential of artificial intelligence, but who grew skeptical about the potential for technology to improve the human condition, died on March 5 in Gröben, Germany. The cause was complications of cancer, said his daughter Sharon Weizenbaum. Eliza, written while Mr. Weizenbaum was a professor at the Massachusetts Institute of Technology in 1964 and 1965 and named after Eliza Doolittle, who learned proper English in "Pygmalion" and "My Fair Lady," was a groundbreaking experiment in the study of human interaction with machines. The program made it possible for a person typing in plain English at a computer terminal to interact with a machine in a semblance of a normal conversation. To dispense with the need for a large real-world database of information, the software parodied the part of a Rogerian therapist, frequently reframing a client's statements as questions.