Programs with Common Sense

UNIVERSITY OF SOUTH CAROLINAUNIVERSITY OF SOUTH CAROLINADepartment of Computer Science and

Engineering

Department of Computer Science and Engineering

Programs with Common Sense

Mingzhe Du and Hongying Du April, 2011

This paper “Programs With Common Sense” was written by John McCarthy in 1959, Stanford University


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Outline

• Programs with common sense• Introduction • Basic Concept• The Construction of Advice Taker: an

example

• Common sense database• Common sense problem


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Why common sense: Software Is BRITTLE

• Example• Google: “Is the Eiffel tower taller than

the Dubai Burj Al Arab?”

• VS

• Eliza: a computer therapist in 1965, MIThttp://www.manifestation.com/

neurotoys/eliza.php3


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Eliza: a computer therapist in 1965, MIT http://www.manifestation.com/neurotoys/eliza.php3


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Eliza: a computer therapist in 1965, MIT http://www.manifestation.com/neurotoys/eliza.php3


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John McCarthy

• born in Boston in 1927• Invention of Lisp• one of the founders of artificial intelligence and knowledge representation.• Programs with Common

Sense – the birth of knowledge representation


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Programs with common sense

• Introduction and Concept• The Construction of Advice Taker: an

example


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• Advice Taker: is a proposed program for solving problems by manipulating sentences in formal languages.

• The basic program will draw immediate conclusions from a list of premises. These conclusions will be either Declarative or Imperative sentences.


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Imperative SentenceWhen an imperative sentence is deduced the

program takes a corresponding action. These actions may include printing sentences, moving sentences on lists, and reinitiating the basic deduction process on these lists.

Declarative Sentence Describing the situation in which action is required

together with a few imperatives that say what is wanted.


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• Main Advantages: we expect the advice taker’s behavior will be improvable merely by making statements to it, telling it about its symbolic environment and what is wanted from it.


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• A program has common sense if it automatically deduces for itself a sufficiently wide class of immediate consequences of anything it is told and what it already knows.


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• “We base ourselves on the idea that: In order for a program to be capable of learning something it must first be capable of being told it.”

-- John McCarthy


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Features an intelligent system should have:• All behaviors must be representable in the

system.• Interesting changes in behavior must be

expressible in a simple way. • All aspects of behavior except the most routine

must be improvable. • The machine must have or evolve concepts of

partial success.• The system must be able to create subroutines

which can be included in procedures as units.


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•Our Ultimate Objective

Make programs that learn from their experience as effectively as humans do.


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• Introduction• The Construction of Advice Taker: an

example


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• An example:• Assume that I am seated at my desk

at home and I wish to go to the airport.

• My car is at my home also. • The solution of the problem is to walk

to the car and drive the car to the airport.


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• 17 Premises• a predicate ``at''. ``at(x,y)'' is a

formalization of ``x is at y''.


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Here prog(y,u) is the program of first carrying out y and then u.


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• Deduction Process• According to

• x: home, y: desk, z: car• We can deduce


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• Similarly, we can get

• Then According to

We can deduce


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• According to

• We can deduce


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• According to

• We can deduce


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• The need for a computer to be able to perform commonsense reasoning

• The need for a computer to have a formal representation of the commonsense

• The representation of such knowledge, along with an inference method to reason with this knowledge, was an essential part of any artificial intelligence



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Controversy

• Philosopher and linguist Yehoshua Bar-Hillel:

• The example of formal commonsense reasoning given in the paper was oversimplified and that any proper formalization of an example would necessarily be much longer and more complex.


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Common sense database: open mind common sense• In 1999, Common Sense Computing

Initiative began at the MIT Media Lab to collect common sense from volunteers on the internet.

• Now, the English site has over a million sentences from over 15,000 contributors.


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A planning problem:The Wolf and the Bush

• A small girl is walking through a forest to visit her grandmother, and she passes a bush behind which a Wolf is hiding, planning to pounce out and eat her. Just as she gets close, however, the Wolf hears the singing of the woodcutters as they start work nearby. The Wolf therefore decides to stay hidden and not pounce on the little girl after all.

• The problem is to explain why the Wolf decides to stay behind the bush.

• Contributed by Pat Hayes and Lokendra Shastri (9th July, 1997)• More examples at http://www-formal.stanford.edu/leora/commonsense/


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Common sense problem

• If one encounters no difficulty along the way, one should be suspicious of the adequacy of the solution.

• It’s more difficult than they appear at first glance.

• Few of the problems listed in that website are currently solvable without considerable simplification.


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References• John McCarthy, Programs With Common Sense,

1959, Mechanisation of Thought Processes, Proceedings of the Teddington Conference on the Mechanization of Thought Processes, 77–84

• Patrick Hayes and Leora Morgenstern, On John McCarthy’s 80th Birthday, in Honor of His Contributions, 2007, AI Magazine 28(4): 93-102

• http://www.aaai.org/AITopics/pmwiki/pmwiki.php/AITopics/CommonSense

• http://openmind.media.mit.edu/• http://www-formal.stanford.edu/leora/

commonsense/

Documents

Programs with Common Sense