artificial intelligence psy 152 5/17/2007. preliminary questions will this material be on the test?...

Artificial Intelligence

PSY 152

5/17/2007

Preliminary Questions

• Will this material be on the test?– Yes.

• Is this material in the textbook?– No.

• Will you put these slides on the course website?– Yes, eventually.

http://psy.ucsd.edu/~jasonjones/sp07psyc152.html

• What if I have a question?– Ask now or come to my office hours.

http://psy.ucsd.edu/~jasonjones/sp07psyc152.html

Lecture Overview

• Why are we talking about AI in this class?

• What is AI?

• How do we know if an artifact is intelligent?

• How should we build intelligent systems?

• Is human intelligence exceptional?

Conceptions of Intelligence:Artificial Intelligence


• “the science and engineering of making intelligent machines”

• “the use of programs to enable machines to perform tasks which humans perform using their intelligence”

• “Multidisciplinary field encompassing computer science, neuroscience, philosophy, psychology, robotics, and linguistics, and devoted to the reproduction of the methods or results of human reasoning and brain activity”


• “A branch of computer science whose goal is the design of machines that have attributes associated with human intelligence, such as learning, reasoning, vision, understanding speech, and, ultimately, consciousness”

• “Computer software that can mimic the learning capability of a human”

• “An algorithm by which a computer gives the illusion of thinking like a human”


• Definition by consensus

• The endeavor to create artifacts that display behavior a reasonable person would describe as intelligent


• Definition by example– Defeating the best human chess players– Driving hundreds of miles through the desert

unaided– Parallel parking– Chatting in internet chatrooms– Examining x-rays for tumors

How do we know if an artifact is intelligent?

• The Turing Test

• A user chats with two unseen entities:– Human– A.I.

• The user must identify the human

Problems with the Turing Test

• The ability to converse is only a subset of intelligence

• Some humans would not pass the Turing Test– e.g. young children or illiterate adults

Demo

• Talking to Eliza:

• http://www-ai.ijs.si/eliza/eliza.html

http://www-ai.ijs.si/eliza/eliza.html

http://www-ai.ijs.si/eliza/eliza.html

When Eliza Worksyoung woman: Men are all alike.

eliza: In what way?

young woman: They're always bugging us about something specific or other.

eliza: Can you think of a specific example?

young woman: Well, my boyfriend made me come here.

eliza: Your boyfriend made you come here?

young woman: He says I'm depressed much of the time.

eliza: I am sorry to hear you are depressed.

young woman: It's true. I'm unhappy.

eliza: Do you think coming here will help you not to be unhappy?

young woman: I need some help, that much seems certain.

Demo

• Twenty questions

• Succeeds by limiting the scope of inquiry


• Deep Blue defeats Gary Kasparov

• First game won: February 10, 1996

• First match won: May 11, 1997

• Kasparov suspected humans were “coaching” Deep Blue


• Is your thermostat intelligent?• Is your dog intelligent?• When your alarm first goes off in the morning,

are you intelligent?


• Dichotomy vs. Continuum

• Dichotomy: Is this entity intelligent – yes or no

• Continuum: Where should we place this entity on the scale of possible intelligence

Rock

Calculator

ASIMO Robot

Cat

Dog Human


• Dichotomy vs. Continuum

• Dichotomy: Is this entity intelligent – yes or no

• Continuum: Where should we place this entity on the scale of possible intelligence

Rock

Calculator

ASIMO Robot

Cat

Dog Human

Your TA

How should we build intelligent systems?

Jacques de Vaucanson’s duck automaton1737


• Intelligence by design– Deep Blue does not play chess the way

humans play chess

• Intelligence by simulation– Neural networks


Build a system to calculate the exclusive or (XOR)

A xor B

Truth Table

A B A xor B

0 0 0

0 1 1

1 0 1

1 1 0


XOR Circuit XOR Neural Net


Design

Pros:• Design may be “whatever

works”• Can be directly inspired by

statistics, computer science and engineering

Cons:• The “AI Effect”• Designing intelligent systems

from scratch may be more difficult than copying existing systems

Simulation

Pros:• Learning about how the brain

may work is a byproduct• Can be directly inspired by

neuroscience and psychologyCons:• Limited to biologically plausible

approaches• Computational power needed

to simulate an intelligent system may exceed power needed to simply behave intelligently

Is human intelligence exceptional?

• Make and use tools


• Self-aware


• Use language to communicate


• Defeating the best human chess players

• Driving hundreds of miles through the desert unaided

• Parallel parking

• Chatting in internet chatrooms

• Examining x-rays for tumors


• The AI Effect – Whenever a feat of intelligence is accomplished by a man-made system, it is no longer seen as truly requiring intelligence.

"Every time we figure out a piece of it, it stops being magical; we say, Oh, that's just a computation."

Rodney Brooks

"As soon as someone gets a computer to do it, people say: 'That's not what we meant by intelligence.' People subconsciously are trying to preserve for themselves some special role in the universe."

Michael Kearns

Demo

• Class vs. Claude Shannon’s mindreader

• http://seed.ucsd.edu/~mindreader/

http://seed.ucsd.edu/~mindreader/


Strong AI – It is possible for machines to truly reason, to represent and interact with the world and to become self aware.

Weak AI – The above is impossible or unattainable, and the focus should be on task-specific AI systems


• The Chinese Room thought experiment– John Searle (1980)


• Rebuttals to the Chinese Room– Perhaps the system as a whole can be said to

“understand” Chinese– Neurons don’t “understand” English


• Computers will reach the processing speeds necessary to simulate brains within 30 years– Raymond Kurzweil


• Kurzweil’s $10,000 bet that a computer will pass a rigorous form of Turing Test by 2029– http://www.longbets.org/1

http://www.longbets.org/1

Summary

• Intelligence is better thought of as a continuum rather than a dichotomy.– The range of human intelligence is a small subset of the range of

possible intelligences

• It remains an open question whether human intelligence is exceptional in kind or only in degree.

• Creating intelligent systems can be approached through design or through simulation.– A better understanding of the concept “intelligence” will follow

from both


PSY 152

5/17/2007

artificial intelligence psy 152 5/17/2007. preliminary questions will this material be on the test?...

Documents

intelligent slide

human slide

artificial intelligence

blue slide

human intelligence exceptional

artificial intelligence

conceptions of intelligence

subset of intelligence