Artificial Intelligence

December 11, 2001

Administrivia

• Assignment 9b is due 5PM Wednesday (12/12)

• Assignment 9c is ready– you need to go to the web site and do the

experiment– for a local research project in web searching– intended to be fun– complete before midnight 12/14

Natural Progression

• You can build a machine– Make the machine replace you

• Roots in science fiction– Androids

• An android is an anthropomorphic robot - i.e. a robot that looks like a human. For example Valerie

• Turing test– Inability to differentiate between human and computer

What do humans do well

• Process information– Language

– Images

• Reason• Create• Relate to other humans• Make intuitive decisions• Enjoy entertainment

What do computers do well

• Process data quickly

• Handle large amounts of data

Computers simulating humans

• Have to understand the process

• Build a good model

• Resolve complexities

Example -- chess

• Number of possible unique chess games is 10120. • In 1957, artificial intelligence pioneers Herbert Simon and

Allen Newell predicted that a computer would beat a human at chess within 10 years.

• BELLE, a chess program by Ken Thompson and Joe Condon, became the first computer to be awarded the title of US chess master, in 1983.

• BELLE didn’t try to do what a human would do. Instead, BELLE took advantage of what computers do well.

• In May 1997, IBM's Deep Blue Supercomputer played a fascinating match with the reigning World Chess Champion, Garry Kasparov and won 3 ½ to 2 ½

Example -- chess

• Does this count as AI?– Computer beating best human– Computer not playing as human would

Other successes

• Language understanding– Eliza 1967

• Speech recognition– Dragon Naturally speaking– Phone company systems– Voice mail systems

• Language translation

Difficulties

• Humans are complex beings and understand– Language issues

• Time flies like an arrow• Fruit flies like a banana

– Searching for tables• Table• table chair

• 98% correct is often not enough– 40 typos in a page

• The search space can get very large

Techniques

• Build a search tree to model the state space• Find good methods of evaluating possibilities• Use your evaluation methods to prune the tree

First steps in TicTacToe

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co rn er s ide

F irs t m o ve

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Turing test

• A person tries to distinguish between a man and a woman (responses over a typewriter). If you replace one by a machine, does the game change?

• A person and a machine are behind a curtain. An interrogator sends questions to each, can the interrogator tell which is which?

Strong AI vs. Weak AI

• strong artificial intelligence states that a computer with the right program would be mental.

• weak artificial intelligence just aims to solve problems, not necessarily to be mental or model human behavior.

MAJOR CITED IDEAS

• Turing test• Universal machines• States in a machine

• Important ideas for AI – symbol system hypothesis– programs that modify behavior – reinforcement learning – attribution of thinking, intelligence – importance of consciousness and reflection– program that surprises– software not hardware the main bottleneck

Turing ideas

• PREDICTIONS:– 50 year conjectures pretty close on hardware – say "machines thinking" without being contradicted– 70% chance of making right identification after 5 minutes of

conversation

• GENERAL SYSTEMS IDEAS:– loops– virtual memory

• BRAIN SCIENCE CONNECTION– chemical and electrical properties of neurons

• Now fMRI, neural nets, …

Work in other sciences

• Neural nets– Build models of machines that think and learn

• Brain mapping– Determine what clumps of neurons do– Eventually map individual neurons

Your questions

• State of art – State of the art in AI

– Technology in general

• Nature of thinking– How does the brain do it?

– Must a machine duplicate the brain?

• What is learning?

• Philosophical– What makes a machine human

• Science Fiction

State of the art

What would happen if we kept asking the Chinese robot why it just gave the answer that it gave an infinite number of times.Could it explain?

For example:Input: How are you today?Output: Good.Input: Why "good"?Output: I'm having a lovely day.Input: Why?Output: I don't know.Input: Why don't you know?...and so on

State of the art

• 1:is there really any way that the computer can create random numbers or is it always just numbers that appear random to a human such as the digits of pi, as cited in the article or for instance e?

Nature of thinking

In the article the author discusses the machine and how it has set rules and guidelines from which it may not deviate. My question is do these rules make the machine nothing like the brain, seeing as the brain has no rules or guidelines to work within, or can these rules and guideline be equated to the capacity an individual's brain has to learn and make sense of problems, ideas, objects, ect.?

Are modern definitions of a computer "thinking by itself" still dependent on continual human programming as the only means of progress, or are there computers somewhere in the distant or even near future that can actually be programmed to program themselves based on input of users or even just experiences (the way that human beings learn and are taught to think)?

Nature of thinking (cont)

• Can machine language and thought be superior to human thought? If so, what does this say for the future of society?

• If scientists can ever figure out the exact code for the brain, would it be possible to simulate it in a strong AI computer?

Learning

• Is it possible for a computer to learn? Can it adapt to unfamiliar situations and "reprogram" itself?

• Because a machine cannot have experiences, how is it that a machine can learn from experiences and acquire the same type of conditioning that humans acquire throughout their lives?

• Could a machine ever write a sonnet with the same intensity and meaning as a human poet or truly enjoy the taste of summer strawberries and cream.

• Can machines ever be programmed to experience emotions?

Philosophical

• We now accept that a computer can beat a chess champion, but we don't easily accept that a computer could experience human emotions in the same way that we do. Is this resistance a general belief that human consciousness is so unique that it could not be replicated by man? Or is it another idea that will be commonly accepted in a few more decades?

• I am not convinced by Turing's counter to the "Arguments fromVarious Diabilites", particularly the question of the computer having itself as the subject of its thoughts.

• If a computer can map out responses through a network of possible answers and connecting ideas, would that make it more human?

Computers vs. humans

• If we create a machine that is a replica of a human brain, using electrons in place of neurotransmitters, is that machine a thinking machine? Even if it cannot think on its own and needs to be able to read the brain activity of a person in order to function. If it is able to follow human neurotransmitter patterns is it thinking or merely copying?

• Is programming a "life history" into a computer possible? (Think about the 3 components of the mind)

• Is if possible for a computer to simulate creativity, which I define as the ability to figure out a solution without the inputs necessary to draw that conclusion from pure logic.

Science Fiction

• Do you think that it will be possible one day to store information in the human's brain or to educate humans by using computer programs?(Like in the movie the Matrix when the main character gets fighting techniques and jump programs stored in his brain)

• I was curious as to how much the technical aspects of the movie AI are plausible-- I'm not talking about the mushy non-technical stuff, but how far are we from robots that look and move- in ways so similar to humans?

• Do you think that if in a point in time we develop machines that could think and be human-kind that they would represent a danger for humans?