Transcript Slides

CMSC 471
Fall 2002
Class #10 – Wednesday, October 12
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Today’s class
• History of AI
– Key people
– Significant events
• Future of AI
– Where are we going
• Philosophy of AI
– Can we build intelligent machines?
• If we do, how will we know they’re intelligent?
– Should we build intelligent machines?
• If we do, how should we treat them…
• …and how will they treat us?
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History of AI
Chronology of AI; Russell & Norvig Ch. 26
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Key people (AI prehistory)
• George Boole invented propositional logic (1847)
• Karel Capek coined the term “robot” (1921)
• Isaac Asimov wrote many sf books and essays (I, Robot (1950)
introduced the Laws of Robotics – if you haven’t read it, you should!)
• John von Neumann: minimax (1928), computer architecture (1945)
• Alan Turing: universal machine (1937), Turing test (1950)
• Norbert Wiener founded the field of cybernetics (1940s)
• Marvin Minsky: neural nets (1951), AI founder, blocks world, Society
of Mind
• John McCarthy invented Lisp (1958) and coined the term AI (1957)
• Allen Newell, Herbert Simon: GPS (1957), AI founders
• Noam Chomsky: analytical approach to language (1950s)
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Key people (early AI history)
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Hubert and Stuart Dreyfus: anti-AI specialists
Ed Feigenbaum: DENDRAL (first expert system, 1960s)
Terry Winograd: SHRDLU (blocks world, 1960s)
Roger Schank: conceptual dependency graphs, scripts
(1970s)
• Shakey: mobile robot (SRI, 1969)
• Doug Lenat: AM, EURISKO (math discovery, 1970s)
• Ed Shortliffe, Bruce Buchanan: MYCIN (uncertainty
factors, 1970s)
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Key events: Genesis of AI
• Turing test, proposed in 1950 and debated ever since
• Neural networks, 1940s and 1950s, among the earliest
theories of how we might reproduce intelligence
• Logic Theorist and GPS, 1950s, early symbolic AI
• Dartmouth University summer conference, 1956,
established AI as a discipline
• Early years: focus on search, learning, knowledge
representation
• Development of Lisp, late 1950s
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Key events: Adolescence of AI
• The movie 2001: A Space Odyssey (1968) brought AI to the public’s
attention
• Early expert systems: DENDRAL, Meta-DENDRAL, MYCIN
• Arthur Samuels’s checkers player, Doug Lenat’s AM and EURISKO
systems, and Werbos’s and Rumelhart’s backpropagation algorithm
held out hope for the ability of AI systems to learn
• Hype surrounding expert systems led to an inevitable decline in interest
in the mid to late 1980s, when it was realized they couldn’t do
everything
• Hype surrounding neural networks in the late 1980s led to similar
disappointment in the 1990s
• Roger Schank’s conceptual dependency theory and Doug Lenat’s Cyc
started to address problems of common-sense reasoning and
representation
• Hans Berliner’s heuristic search player defeated the world
backgammon champion in 1979
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Key events: AI adulthood (barely)
• Many commercial expert systems introduced, especially in
the 1970s and 1980s
• Fuzzy logic and neural networks used in controllers,
especially in Japan and Europe
• Recent developments and areas of great interest include:
– Bayesian reasoning and Bayes nets
– Ontologies, knowledge reuse, and knowledge acquisition
– Mixed-initiative systems that combine the best of human and
computer reasoning
– Multi-agent systems, Internet economies, intelligent agents
– Autonomous systems for space exploration, search and rescue,
hazardous environments
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Are we there yet?
• Great strides have been made in knowledge representation
and decision making
• Many successful applications have been deployed to (help)
solve specific problems
• Key open areas remain:
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Incorporating uncertain reasoning
Real-time deliberation and action
Perception (including language) and action (including speech)
Lifelong learning / knowledge acquisition
Common-sense knowledge
Methodologies for evaluating intelligent systems
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Philosophy of AI
Alan M. Turing, “Computing Machinery and
Intelligence”
John R. Searle, “Minds, Brains, and Programs”
(also: Russell & Norvig Ch. 27)
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Philosophical debates
• What is AI, really?
– What does an intelligent system look like?
– Does an AI need—and can it have—emotions, consciousness,
empathy, love?
• Can we ever achieve AI, even in principle?
• How will we know if we’ve done it?
• If we can do it, should we?
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Turing test
• Basic test:
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Interrogator in one room, human in another, system in a third
Interrogator asks questions; human and system answer
Interrogator tries to guess which is which
If the system wins, it’s passed the Turing Test
• The system doesn’t have to tell the truth (obviously…)
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Turing test objections
• Objections are basically of two forms:
– “No computer will ever be able to pass this test”
– “Even if a computer passed this test, it wouldn’t be intelligent”
• Chinese Room argument (Searle, 1980), responses, and
counterresponses
– Robot reply
– Systems reply
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“Machines can’t think”
• Theological objections
• “It’s simply not possible, that’s all”
• Arguments from incompleteness theorems
– But people aren’t complete, are they?
• Machines can’t be conscious or feel emotions
– Reductionism doesn’t really answer the question: why can’t
machines be conscious or feel emotions??
• Machines don’t have Human Quality X
• Machines just do what we tell them to do
– Maybe people just do what their neurons tell them to do…
• Machines are digital; people are analog
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“The Turing test isn’t meaningful”
• Maybe so, but…
If we don’t use the Turing test, what
measure should we use?
• Very much an open question…
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Ethical concerns: Robot behavior
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How do we want our intelligent systems to behave?
How can we ensure they do so?
Asimov’s Three Laws of Robotics:
1. A robot may not injure a human being or, through inaction, allow a
human being to come to harm.
2. A robot must obey orders given it by human beings except where
such orders would conflict with the First Law.
3. A robot must protect its own existence as long as such protection
does not conflict with the First or Second Law.
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Ethical concerns: Human behavior
• Is it morally justified to create intelligent systems with these
constraints?
– As a secondary question, would it be possible to do so?
• Should intelligent systems have free will? Can we prevent
them from having free will??
• Will intelligent systems have consciousness? (Strong AI)
– If they do, will it drive them insane to be constrained by artificial
ethics placed on them by humans?
• If intelligent systems develop their own ethics and morality,
will we like what they come up with?
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