Marvin Minsky, MIT professor and AI's founding father, says today's artificial-intelligence methods are fine for gluing together two or a few knowledge domains but still miss the "big" AI problem. Indeed, according to Minsky, the missing element is something so big that we can't see it: common sense.
"To me the problem is how to get common sense into computers," said Minsky. "And part of that, it seems to me, is not how to solve any particular problem but how to quickly think of a new way to solve it-perhaps through a change in emotional state-when the usual method doesn't work."
In his forthcoming book, The Emotion Machine, Minsky shares his accumulated knowledge on how people make use of common sense in the context of discovering that missing cognitive glue. For instance, "scripting," according to Minsky, lets people reuse procedural knowledge in different contexts by tweaking its parameters. Parking your car in an unfamiliar spot is an example: You adapt on the fly using the knowledge base gained in previous parking experiences.
But "the big feature of human-level intelligence is not what it does when it works but what it does when it's stuck," Minsky said. When faced with novelty, Minsky claims, human intelligence applies "reasoning by analogy" to make the most direct tap into the cognitive glue that fuses knowledge domains.
Reasoning by analogy is a way of adapting old knowledge, which almost never perfectly matches the present situation, by following a recipe of detecting differences and tweaking parameters. It all happens so quickly that no "thinking" seems to be involved.
One group hot on the trail of Minsky's vision of common sense is spearheaded by Doug Lenat, a former professor at Carnegie-Mellon and Stanford Universities who is now president of Cycorp, maker of the Cyc (pronounced "psych") knowledge base. Since 1984, Cyc has accumulated 1 million rules in its knowledge base of common sense. According to Lenat, Cycorp's stated goal is to "break the software brittleness bottleneck once and for all by constructing a foundation of basic common-sense knowledge-a semantic substratum of terms, rules and relations, a deep layer of understanding that can be used by other programs to make them more flexible."
Minsky quotes Lenat on what constitutes common sense as knowledge: "In modern America, this encompasses recent history and current affairs, everyday physics, household chemistry, famous books and movies and songs and ads, famous people, nutrition, addition, weather, etc."
In The Society of Mind (New York: Simon and Schuster, 1987), Minsky proposed that intelligence is the product of a managed interaction among a diverse variety of resourceful agents. And in The Emotion Machine, Minsky maintains that the roles played by feelings, goals, emotions and conscious thoughts motivate and regulate activities within our "personal" societies of mind.