Announcements

1
Announcements

• The Thinking Machine airs
• Today (9/6) at 4PM on channel 53
• Monday (9/10) at 3 and 8PM on channel 53
• Homework 1 due Tuesday, 9/11 write up on The
  Thinking Machine
• Lab 0 due Thursday, September 13

2
Introduction to Artificial Intelligence

• Lecture 2

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What is Artificial Intelligence?

• Systems that think like humans
• Systems that act like humans
• Systems that think rationally
• Systems that act rationally

4
What has AI accomplished?
5
What will AI accomplish?
6
The Beginnings

• 1942 Isaac Asimov publishes the three laws of
  robotics
• 1950 Alan Turing publishes the Turing Test, a
  means of determining if a machine can think
• 1956 The term Artificial Intelligence is coined
  at a meeting at Dartmouth College

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The Turing Test

• Uses the "Imitation Game"
• Usual method
• Three people play (man, woman, and interrogator)
• Interrogator determines which of the other two is
  a woman by asking questions
• Example How long is your hair?
• Questions and responses are typewritten or
  repeated by an intermediary
• Turing Test
• Machine takes the part of the man

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Strength of the Test

• "The new problem has the advantage of drawing a
  fairly sharp line between the physical and the
  intellectual capacities of a man" (Turing, 1950)

9
Debating the question "Can machines think?"

• The Theological Objection
• Thinking is a function of man's immortal soul
• The "Head in the Sand" Objection
• The consequences of machines thinking would be
  too dreadful
• The Mathematical Objection
• Given the limitations to the powers of
  discrete-state machines, there are some questions
  to which it will either give the wrong answer or
  fail to answer

10
Debating the question "Can machines think?"

• The Argument from Consciousness
• "Not until a machine can write a sonnet or
  compose a concerto because of thoughts and
  emotions felt, could we agree that machine
  equals brain" (Jefferson, 1949)
• Arguments from Various Disabilities
• "I grant you that you can make machines do all
  the things you mentioned but you will never be
  able to make one do X"
• X be kind, resourceful, friendly,

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Debating the question "Can machines think?"

• Lady Lovelace's Objection
• "The Analytical Engine has no pretensions to
  originate anything. It can do whatever we know
  how to order it to perform"
• The Argument from Continuity in the Nervous
  System
• Given that the nervous system is not a
  discrete-state machine, you cannot mimic the
  behavior of nervous system with a discrete-state
  machine.

12
Debating the question "Can machines think?"

• The Argument from Informality of Behavior
• It is not possible to produce a set of rules
  purporting to describe what a man should do in
  every conceivable set of circumstances. Thus it
  is not possible that humans are machines.
• The Argument from Extrasensory Perception
• Assuming the woman has ESP, she could perform
  better on a test of clairvoyance than the machine
• Use a telepathy-proof room

13
Recent Experiment

• Spring, 2005 3 undergrads from Simons Rock
  College (Bard, MA) conducted the first
  gender-twisting Turing Test
• Setup
• Round 1 Participant has 5 minutes to chat with a
  woman and a man masquerading as a women
• Round 2 Participant has 5 minutes to chat with a
  woman and ALICE
• Female chat bot developed by Richard Wallace

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Sample interaction

• Subject What do girls do at sleepovers?
• Bot They do their own thing.
• Subject Do you wear skirts?
• Bot Only when I dress up.
• Subject You are a female.

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Outcomes

• 42 participants
• 23 didnt give any indication that they suspected
  ALICE was not a real person
• Some did suspect ALICE
• Subject Are you a computer?
• Bot Would it matter to you if I were metal
  instead of flesh?
• Question that tripped up men and bot
• Subject What size panty hose do you wear?

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What does it mean if a computer passes the Turing
Test?

• Can the computer think?
• Does the computer have a mind in exactly the same
  sense that you and I have minds?

17
Chinese Room

• Thought experiment purposed by John Searle in
  1980
• Given that we have constructed a machine that
  behaves as though is understands Chinese, it
  convinces a Chinese speaker that it speaks
  Chinese
• Given Chinese symbols, it consults a look-up
  table and produces other Chinese symbols as output

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Chinese Room substitution

• Machine is replaced by Searle sitting in a room
  where he receives Chinese symbols, looks them up
  on a look-up table, and returns the Chinese
  symbol indicated by the table
• English speaker can now give correct answers to
  Chinese questions without understanding Chinese
• Since Searle doesn't understand Chinese, how can
  it be said that the computer understands Chinese?

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Systems Reply

• Although Searle himself doesn't understand
  Chinese, it is reasonable to say that Searle plus
  look-up table understand Chinese
• Counter example he memorized the look-up table
  before entering the room

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Robot Reply

• The reason that we don't want to attribute
  understanding to the room, or a computer is that
  the system doesn't interact properly with the
  environment
• Solution put the computer in a robot so that it
  can interact with the world
• Reply Cognition is not symbol manipulation.
  Second, Searle could be inside the robot and
  still not understand Chinese

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Chinese Room Conclusion

• The mind is not a computer
• Thus the Turing Test is inadequate

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How would you show that a machine can think?
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Additional Sources

• Generation5's interview with John Searle (2001).
• http//www.generation5.org/content/2001/searle.asp
  
• Eliasmith, C. Chinese room.
• http//www.artsci.wustl.edu/7Ephilos/MindDict/chi
  neseroom.html
• McCarthy, J, et al. A proposal for the Dartmouth
  Summer Research Project on Artificial
  Intelligence. 1955.
• http//www-formal.Stanford.EDU/jmc/history/dartmou
  th.html
• Moravec, H. Robot Mere Machine to Transcendent
  Mind. Oxford University Press, Inc. 1999.
• Tompson, C. The Other Turing Test. Wired,
  13.07, 2005.
• http//www.wired.com/wired/archive/13.07/posts.htm
  l?pg5
• Turing, A. Computing machinery and intelligence.
  Mind, 59, 433-460.
• http//www.loebner.net/Prizef/TuringArticle.html