physical symbol system hypothesis presentation

8/14/2019 physical symbol system hypothesis presentation

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Physical Symbol SystemHypothesis

Gagan Deep Kaur

Roll No. 07408802

Course Seminar - CS 344


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Physical Symbol System

A PSS consists of

- Symbols - set of entities that are physical patterns

- Symbol Structures - number of instances/tokens related in

some physical way- Processes operate on these expressions to produce other

expressions


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S6S5S4S3S2S1

Symbol

Symbol

Structures -Expressions

S1

CC$7899ABVV


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S6S5S4S3S2S1

Collection ofExpressions

S12S11

S10S9S8S7

S18S17S16S15S14S13

S24S23S22S21S20S19

S30S29S28S27S26S25

At any given time, a PSS contains- collection of expressions- processes to operate on these expressions

creation, modification, reproduction, destruction


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Physical Symbol System

Key Concepts

Designation the symbol/expressions can refer to somethingelse.

Interpretation the expressions can refer to its owncomputational processes which the system can evoke andexecute


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Examples of Symbol Systems

System Symbol Expressions Processes

Logic And, Or, Not, Propositions (T/F) Rules of Inference

Algebra +, -, *, /,y, z, 1, 2, 3.

Equations(2+3=5)

Rules of Algebra

Digital Computer 0, 1 00000111000.. Program

-----Chess Chess Pieces Position of pieceson the board

Legal ChessMoves


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Physical Symbol System Hypothesis

- By Allen Newell and Herbert Simon

A physical symbol system has the necessary

and sufficient means for general intelligent action


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Claims

- Human thinking is a kind of symbol manipulation

- Symbol manipulation necessary for intelligence

- Machines can be intelligent, because

- Symbol manipulation is sufficient for intelligence

Core assumption of Strong AI


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Grounds of PSS

Brain similar with a physical symbol system

Psychological Experiments decision making, learning processes

Running AI programs chess, checkers, theorem proving,

Clark Productivity of Human Thoughts


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Examples of PSS

System Symbol Expressions Processes

Digital Computer 0, 1 00000111000.. Program

-----Chess Chess Pieces Position of pieces

on the board

Legal Chess

Moves

Brain Encoded in brain Thoughts Mental Operationslike thinking

AI Program Data Data Data


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Merits

Computationally possible to encode symbolic humanknowledge

Opened avenue for machine intelligence!


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Implications

Appropriately programmed computer is capable of consciousthought

Machines can be made to think and have genuineunderstanding

Can Physical Symbol Systems Think?


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symbol manipulation = intelligence?


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Critiques

Serial manipulation of parallel and distributeddiscrete symbols processing

(PSS) (Human Brain)

Dreyfus Role of unconscious instincts than conscious symbolmanipulation


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Searles Chinese Room


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Intelligence requires Understanding.

Does the program understands the symbols that it uses?

Does symbols have any meaning for the machine?


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Conclusion

The question thus boiled down to this:

Could a system think or understand just by having right sortof program?

Is syntax enough to ensure semantics which is necessaryfor understanding.


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Can Physical Symbol System be

Intelligent?


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References

Clark, Andy, Philosophical Implications,Artificial Intelligence, Ed. MargaretBoden, Academic Press, California, 1996

Dreyfus, Hubert, What Computers Cant Do: The Limits of AI, Harper & Row,New York, 1979

Newell, Allen and Simon, Herbert, Computer Science and Empirical Inquiry:Search and Symbols, Mind Design II, Ed.John Hagueland, MIT Press, 1997,

Searle, John, Minds, Brains and Programs, Minds I, Ed. Douglas Hofstadter,and Daniel Dennett, Basic Books, 2001, P. 282-306

Wikipedia, Stanford Encyclopedia

Various Internet Sources For The Pictures!

Documents

physical symbol system hypothesis presentation