Probabilistic Computational Intelligence: The World Is Gray, Not Black and White

John Markoff, Behind Artificial Intelligence, a Squadron of Bright Real People, NYTimes Online (Oct. 14 2005):

While artificial intelligence technology is already in use in telephone answering systems with speech recognition and in popular household gadgets like the iRobot vacuum cleaner, none of the existing systems have been as ambitious as Darpa's Grand Challenge road race.

This leap was possible, in large part, because researchers are moving from an approach that relied principally on logic and rule-based systems to more probability or statistics-oriented software technologies.

"In the past A.I. has been dominated by symbolic systems and now the world is gray," said Terrence J. Sejnowski, head of the computational neurobiology laboratory at the Salk Institute in La Jolla, Calif. "That's what it's like to deal with the real world."

N.B. Probability theory is essential. But it's not the whole story. And probability theory may not be the only coherent and effective mathematical strategy for dealing with uncertainty and shades of gray.