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

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

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”

Artificial Intelligence “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”

Artificial Intelligence Definition by consensus The endeavor to create artifacts that display behavior a reasonable person would describe as intelligent

Artificial Intelligence 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:

When Eliza Works young 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

How do we know if an artifact is intelligent? Deep Blue defeats Gary Kasparov First game won: February 10, 1996 First match won: May 11, 1997 Kasparov suspected humans were “coaching” Deep Blue

How do we know if an artifact is intelligent? Is your thermostat intelligent? Is your dog intelligent? When your alarm first goes off in the morning, are you intelligent?

How do we know if an artifact is 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 DogHuman

How do we know if an artifact is 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 DogHuman Your TA

How should we build intelligent systems? Jacques de Vaucanson’s duck automaton 1737

How should we build intelligent systems? Intelligence by design –Deep Blue does not play chess the way humans play chess Intelligence by simulation –Neural networks

How should we build intelligent systems? Build a system to calculate the exclusive or (XOR) A xor B Truth Table ABA xor B

How should we build intelligent systems? XOR CircuitXOR Neural Net

How should we build intelligent systems? 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 psychology Cons: 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

Is human intelligence exceptional? Self-aware

Is human intelligence exceptional? Use language to communicate

Is human intelligence exceptional? 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

Is human intelligence exceptional? 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

Is human intelligence exceptional? 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

Is human intelligence exceptional? The Chinese Room thought experiment –John Searle (1980)

Is human intelligence exceptional? Rebuttals to the Chinese Room –Perhaps the system as a whole can be said to “understand” Chinese –Neurons don’t “understand” English

Is human intelligence exceptional? Computers will reach the processing speeds necessary to simulate brains within 30 years –Raymond Kurzweil

Is human intelligence exceptional? Kurzweil’s $10,000 bet that a computer will pass a rigorous form of Turing Test by 2029 –

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

Artificial Intelligence PSY 152 5/17/2007