CS 484
–
Artificial Intelligence
1
Announcements
•
The Thinking Machine airs
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Today (9/6) at 4PM on channel 53
•
Monday (9/10) at 3 and 8PM on channel 53
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Homework 1 due Tuesday, 9/11
–
write up
on The Thinking Machine
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Lab 0 due Thursday, September 13
Introduction to
Artificial Intelligence
Lecture 2
CS 484
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Artificial Intelligence
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What is Artificial Intelligence?
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Systems that think like humans
•
Systems that act like humans
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Systems that think rationally
•
Systems that act rationally
CS 484
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Artificial Intelligence
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What has AI accomplished?
CS 484
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Artificial Intelligence
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What will AI accomplish?
CS 484
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Artificial Intelligence
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The Beginnings
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1942
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Isaac Asimov publishes the three
laws of robotics
•
1950
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Alan Turing publishes the
Turing
Test
, a means of determining if a machine
can think
•
1956
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The term Artificial Intelligence is
coined at a meeting at Dartmouth College
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Artificial Intelligence
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The Turing Test
•
Uses the "Imitation Game"
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Usual method
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Three people play (man, woman, and interrogator)
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Interrogator determines which of the other two is a
woman by asking questions
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Example: How long is your hair?
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Questions and responses are typewritten or repeated
by an intermediary
•
Turing Test
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Machine takes the part of the man
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Artificial Intelligence
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Strength of the Test
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"The new problem has the advantage of
drawing a fairly sharp line between the
physical and the intellectual capacities of a
man"
(Turing, 1950)
CS 484
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Artificial Intelligence
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Debating the question
"Can machines think?"
•
The Theological Objection
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Thinking is a function of man's immortal soul
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The "Head in the Sand" Objection
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The consequences of machines thinking would be too
dreadful
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The Mathematical Objection
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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
CS 484
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Artificial Intelligence
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Debating the question
"Can machines think?"
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The Argument from Consciousness
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"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"
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X = be kind, resourceful, friendly, …
CS 484
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Artificial Intelligence
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Debating the question
"Can machines think?"
•
Lady Lovelace's Objection
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"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
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Given that the nervous system is not a discrete
-
state
machine, you cannot mimic the behavior of nervous
system with a discrete
-
state machine.
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Artificial Intelligence
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Debating the question
"Can machines think?"
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The Argument from Informality of Behavior
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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
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Assuming the woman has ESP, she could perform
better on a test of clairvoyance than the machine
•
Use a telepathy
-
proof room
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Artificial Intelligence
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Recent Experiment
•
Spring, 2005 3 undergrads from Simon’s
Rock College (Bard, MA) conducted the
first “gender
-
twisting” Turing Test
•
Setup
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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
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Female chat bot developed by Richard Wallace
CS 484
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Artificial Intelligence
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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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Artificial Intelligence
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Outcomes
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42 participants
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23 didn’t 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?
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Question that tripped up men and bot
•
Subject
:
What size panty hose do you wear?
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Artificial Intelligence
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What does it mean if a computer
passes the Turing Test?
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Can the computer think?
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Does the computer have a mind in exactly
the same sense that you and I have minds?
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Artificial Intelligence
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Chinese Room
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Thought experiment purposed by John
Searle in 1980
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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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Artificial Intelligence
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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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Artificial Intelligence
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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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Artificial Intelligence
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Robot Reply
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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
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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
CS 484
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Artificial Intelligence
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Chinese Room Conclusion
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The mind is not a computer
•
Thus the Turing Test is inadequate
CS 484
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Artificial Intelligence
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How would you show that a
machine can think?
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Artificial Intelligence
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Additional Sources
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Generation5's interview with John Searle (2001).
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http://www.generation5.org/content/2001/searle.asp
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Eliasmith, C. Chinese room.
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http://www.artsci.wustl.edu/%7Ephilos/MindDict/chineseroom.html
•
McCarthy, J, et al. A proposal for the Dartmouth Summer Research
Project on Artificial Intelligence. 1955.
•
http://www
-
formal.Stanford.EDU/jmc/history/dartmouth.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.html?pg=5
•
Turing, A. Computing machinery and intelligence. Mind, 59, 433
-
460.
•
http://www.loebner.net/Prizef/TuringArticle.html
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