Lecture #23 (9 April 2002)

Introduction to Artificial Intelligence ("AI")

Overall Reading
Brookshear: Ch. 10.1, 10.7
Decker/Hirshfield: Mods. 9.1-9.3, 9.5

Outline:

  • Preface (Ch. 10.1 [Br]; Mod. 9.1 [DH])
  • Definitions of Artificial Intelligence (Ch. 10.1 [Br]; Mod. 9.2 [DH])
  • Academics
  • Hollywood
  • Human Intelligence (Mod. 9.3 [DH])
  • Consequences (Ch. 10.7 [Br]; Mod. 9.5 [DH])

    • Preface

    In the coming weeks, we will examine questions of the following type:

  • Name some tasks that might be difficult for computers to accomplish?





  • Are there tasks which humans do better than computers?





  • Name a job, performed by a human, which you think could never be filled by a machine.





  • Are there computational tasks which neither computers nor humans can accomplish?





    •

    Definitions of Artificial Intelligence (Ch. 10.1 [Br]; Mod. 9.2 [DH])

  • Academia
    In general, the concept of computers and intelligence was brought to the forefront by Alan Turing in a 1950 paper entitled "Computing Machinery and Intelligence."

    Further work came out of a 1956 workshop at Dartmouth College sponsored by John McCarthy. In the proposal for this workshop, McCarthy used the phrase a "study of artificial intelligence."

    Three views of research within AI:

  • Weak AI: machines can be programmed to exhibit intelligent behavior.

  • Marvin Minsky: AI is "the science of making machines do things that would require intelligence if done by man."

  • The Turing Test: You are having a conversation in a 'chat room' on the web. Can you be sure whether the responses you see are generated by a human or a computer?

    If computers are ever so good at participating in coversations that you can not distinguish, then Turing says that the computer has displayed intelligence

  • Strong AI: machines can be programmed to possess intelligence and consciousness.

    Curiously, if someone claims to have a machine which possesses intelligence and consciousness, how can they prove it? How can you disprove the claim?

    We credit other humans with intelligence and consciousness, not because we are sure that they have thoughts and emotions, but because they behave as if they do.

  • Computational models of human intelligence

  • Patrick Hayes: AI is "the study of intelligence as computation."
    •

    Can we produce a legitimate model of the workings of the human brain? We seem to know that the brain is made up of many neurons which are interconnected. Each individual neuron has a reasonably simple behavior. It is the complex combination of them all that we don't understand.

    A comparison:

  • Brains have roughly 50 trillion bits of memory
    roughly 100 billion neurons
    with each neuron connected to roughly 1000 other neurons
    chemicals called neurotransmitters travel at the rate of perhaps 1000 feet per second.

  • Massively parallel computers have roughly similar amount of memory
    electrons travel essentially at speed of light
    but processors connected perhaps to 100 other processors.

  • Hollywood interpretations?
  • 2001: A space Oddysey ("You don't mind talking about this, do you Dave?")
  • War Games ("Shall we play a game?")
  • Short Circuit ("Number five is alive!")
  • Terminator
  • Artificial Intelligence

    • Human Intelligence (Mod. 9.3 [DH])

    Why do we consider humans to be intelligent?

    What exactly do we do to earn that label?
    What are your views of mammals? birds? insects? amoebae? plants?
    What about machines?

  • Thinking Effortlessly: (language, vision)
    Do you consciously think about how to interpret each word and sentence of a conversation or do you just hear it?

    When you look out a window and see a tree, did you reason to figure out you are seeing a tree, or do you just know it?

  • Thinking Deeply: (analogies, metaphors)
    We can quickly relate situations to previous knowledge and experiences.

    "Thinking about this topic is like pulling teeth"

  • Thinking Hard: (conscious train of thought)

    "Three wolves and three chickens have to cross a river using a boat which can only hold two animals at a time..."

  • Creativity

    • Consequences (Ch. 10.7 [Br]; Mod. 9.5 [DH])

    What are the moral and philosophical issues?

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    Last modified: Mon Apr 1 21:05:14 CST 2002