CMSC 471 Fall 2004

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CMSC 471Fall 2004

• Class 14 Tuesday, October 19

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Todays 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 theyre 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 havent 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)

• 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 publics attention
• Early expert systems DENDRAL, Meta-DENDRAL,
  MYCIN
• Arthur Samuelss checkers player, Doug Lenats AM
  and EURISKO systems, and Werboss and Rumelharts
  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 couldnt do
  everything
• Hype surrounding neural networks in the late
  1980s led to similar disappointment in the 1990s
• Roger Schanks conceptual dependency theory and
  Doug Lenats Cyc started to address problems of
  common-sense reasoning and representation
• Hans Berliners 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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What do AI people do?

• Subject headings from IJCAI-01 conference
  proceedings
• Knowledge Representation and Reasoning
• Search, Satisfiability, and Constraint
  Satisfaction
• Cognitive Modeling
• Planning
• Games
• Diagnosis
• Logic Programming and Theorem Proving
• Uncertainty and Probabilistic Reasoning
• Neural Networks and Genetic Algorithms
• Machine Learning and Data Mining
• Case-Based Reasoning
• Multi-Agent Systems
• Natural Language Processing and Information
  Retrieval
• Robotics and Perception
• Web Applications

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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
• 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

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Philosophical debates

• What is AI, really?
• What does an intelligent system look like?
• Does an AI needand can it haveemotions,
  consciousness, empathy, love?
• Can we ever achieve AI, even in principle?
• How will we know if weve done it?
• If we can do it, should we?

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Turing test

• Basic test
• 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, its passed the Turing Test
• The system doesnt 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 wouldnt
  be intelligent
• Chinese Room argument (Searle, 1980), responses,
  and counterresponses
• Robot reply
• Systems reply

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Machines cant think

• Theological objections
• Its simply not possible, thats all
• Arguments from incompleteness theorems
• But people arent complete, are they?
• Machines cant be conscious or feel emotions
• Reductionism doesnt really answer the question
  why cant machines be conscious or feel
  emotions??
• Machines dont 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 isnt meaningful

• Maybe so, but
• If we dont use the Turing test, what measure
  should we use?
• Very much an open question

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Ethical concerns Robot behavior

• How do we want our intelligent systems to behave?
• How can we ensure they do so?
• Asimovs Three Laws of Robotics
• A robot may not injure a human being or, through
  inaction, allow a human being to come to harm.
• A robot must obey orders given it by human beings
  except where such orders would conflict with the
  First Law.
• 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?