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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. Introduction to Artificial Intelligence. Lecture 2.
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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 CS 484 – Artificial Intelligence
Introduction to Artificial Intelligence Lecture 2
What is Artificial Intelligence? • Systems that think like humans • Systems that act like humans • Systems that think rationally • Systems that act rationally CS 484 – Artificial Intelligence
What has AI accomplished? CS 484 – Artificial Intelligence
What will AI accomplish? CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
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) CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
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, … CS 484 – Artificial Intelligence
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. CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
Recent Experiment • Spring, 2005 3 undergrads from Simon’s 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 CS 484 – Artificial Intelligence
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. CS 484 – Artificial Intelligence
Outcomes • 42 participants • 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? • Question that tripped up men and bot • Subject: What size panty hose do you wear? CS 484 – Artificial Intelligence
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? CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
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? CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
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 CS 484 – Artificial Intelligence
Chinese Room Conclusion • The mind is not a computer • Thus the Turing Test is inadequate CS 484 – Artificial Intelligence
How would you show that a machine can think? CS 484 – Artificial Intelligence
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/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 CS 484 – Artificial Intelligence