Lecture
33
Final Examination
Tuesday, May 15
9 am - Noon
Hemicycle
Handout: Cryptology Worksheet II Solutions
Extra Credit Problems Due Friday
Tomorrow's Sessions /No Office
Hours Today
Breaking the Code
What is the place of humans in nature?
Humans have attempted to locate themselves by comparison a with those things in nature most similar to themselves, i.e., other animals.
The problem of determining whether animals are conscious stretches the limits of knowledge and scientific methodology
The question of whether animals
are conscious beings is of considerable moral significance given the dependence
of modern societies on mass farming and the use of animals for biomedical
research.
of Artificial Intelligence:
Natural Language Processing: Can Computers Converse with People?
Computer Understanding: Can A Computer Read and "Understand" a Newspaper Article?
Can Computers Translate Languages?
Can Computers Play Games Well?
Can Computers Learn?
Natural Language Processing:
Can Computers Converse with People?
Jospeh Weizenbaum
Joseph Weizenbaum, "ELIZA--A Computer Program for the Study of Natural Language Communication Between Man and Machine," Communications of the ACM, 9 (1): 36-45.
http://i5.nyu.edu/~mm64/x52.9265/january1966.html
Men are all alike.
In what way?
They're always bugging us about something or other.
Can you think of a specific example?
Well, my boyfriend made me come here.
Your boyfriend made you come here
He says I'm depressed much of the time.
I am sorry to hear you are depressed
It's true. I am unhappy
Do you think coming here will help you not to be unhappy
I need some help, that much seems certain.
What would it mean to you if you got some help
Perhaps i could learn to get along with my mother.
Tell me more about your family.
My mother takes care of me.
Who else in your family takes care of you?
My father.
Your father
You are like my father in some ways.
What resemblance do you see?
You are not very aggressive but i think you don't want me to notice that.
What makes you think I am not very aggressive?
You don't argue with me.
Why do you think I don't argue with you?
You are afraid of me.
Does it please you to believe I am afraid of you?
My father is afraid of everybody.
What else comes to your mind when you think of your father?
Bullies.
Does that
have anything to do with the fact that your boyfriend made you come here?
Eliza was designed to be a "Rogerian psychologist"
Nondirectve therapy
Therapist provides no formal guidance
Simply let the patient talk; keep the conversation going.
Reactions to Weizenbaum's program:
Some practicing psychiatrists seriously believed Eliza could be expanded into an automated psychotherapist.
People quickly and deeply became emotionally involved. ("Eliza understands and cares."
ELIZA demonstates
a general solution to the problem of computer understanding of natural
language.
Weizenbaum:
"Extremely short exposures to a relatively simple program can induce powerful
delusional thinking in quite normal people."
Computer Power and Human Reason
Interesting recent review: http://www.gslis.utexas.edu/~palmquis/courses/reviews/amy.htm
Interview with weizenbaum:
http://www-tech.mit.edu/V105/N16/weisen.16n.html
Computer Understanding: Can A Computer Read and "Understand" a Newspaper Article?
Roger C. Schank and Robert P. Abelson
(1977). Scripts, Plans, Goals and Understanding: an Inquiry into Human
Knowledge Structures, Erlbaum, Hillsdale, NJ
Roger Schank
SAM (S)cript (A)pplier (M)echanism.
Sam "reads" short stories and then answers questions about the stories that it reads to test its comprehension.
The Story
John went to New York by bus. On
the bus he talked to an old lady. When he left the bus, he thanked the
driver. He took the subway to Leone's. On the subway his pocket was picked.
He got off the train and entered Leone's. He had some lasagne. When the
check came, he discovered that he couldn't pay. The management told him
he would have to wash dishes. When he left, he caught a bus to New Haven.
The Test
Why did John go to New York?
How did John go to Leone's?
Did anything unusual happen on the bus?
Did anything unusual happen on the subway?
What did John order?
Did anything unusual happen at the restaurant?
Why couldn't John pay the check?
Why didn't John have any money?
How did John get back to New Haven?
How was
John able to take the bus to New Haven?
Q: Why did John go to New York?
A: Because John wanted to go to Leone's.
Q: How did John go to Leone's?
A: John took a bus to New York and then he took the subway to Leone's.
Q: Did anything unusual happen on the bus?
A: I don't remember anything.
Q: Did anything unusual happen on the subway?
A: A thief picked John's pocket.
Q: What did John order?
A: John ordered lasagne.
Q: Did anything unusual happen at the restaurant?
A: John discovered that he couldn't pay the check and so he had to wash dishes.
Q: Why couldn't John pay the check?
A: Because John did not have any money.
Q: Why didn't John have any money?
A: Because a thief picked John's pocket.
Q: How did John get back to New Haven?
A: John went from Leone's by subway and then he went to New Haven by bus.
Q: How was John able to take the bus to New Haven?
A: Probably John had a ticket.
How Did Sam Do It?
How was Sam able to answer all of those questions? After all, the questions concerned information that wasnot explicit in the information given in the story, yet Sam was able to infer that John had no money becausehis pocket was picked, had to do dishes because he had no money to pay his check, probably was able to takethe bus back to New Haven because he already had a ticket even though he had no money, and so on.
The answer is that Sam is a program that is able access a variety of Scripts that have information about what is typical in certain situations. For example, a restaurant script, a bus script, and so on. When Sam is asked a question to which the answer is not implicit in the story, Sam consults the appropriate script and fills in the missing material as best it can.
So, does Sam understand the story?
Well, Schank didn't think so, and he helped write Sam's program.
Can Computers
Play Games Well?
http://www.research.ibm.com/deepblue/
http://www.research.ibm.com/deepblue/home/html/b.html
1951: Alan Turing discusses the concept of an 'evaluation function" for chess and how this could be used to have a computer play chess.
1966: Mahack at MIT was the first computer to defeat a human being.
1988: HITECH (Carneigie-Mellon) becomes first chess program to rank as Senior Master.
1989: Deep THought (Feng Hsiang Hsu at Carnegie-mellon) becomes first computer to achieve U. S. Chess Federation performance rating of 2500. Beats a Grandmaster, but is beaten by Kasparov and Karpov. (Looks ahead 10-11 levels).
1990: Deep Thought (IBM) can beat all but top 200 chess players in world on regular basis.
1993: Deep Thought II: Beats 20th ranked Grandmaster. (IBM RS/6000 computer). (looks ahead 14 levels).
1996: Deep Blue in touranment with Garry Kasparov. Beats Kasparov in early game, but loses series narrowly.
1997:
Deep Blue wins by 3.5 to 2.5. ("The end of mankind" says Kasparov).
RS/6000 technology now tackles complex "real world" problems
Cleaning up toxic waste sites
Forecasting the weather
Modeling financial data
Designing cars
Developing innovative drug therapies
Can Computers Learn?
Tom M. Mitchell, "Does Machine Learning
Really Work? AI Magazine, Fall 1997 v18 n3 p11(10)
