how expensive a logical agent is
DESCRIPTION
Presentation based on Programs with Common Sense by John McCarthy. Done by Dileepa Fernando and Rashmika Nawaratne.TRANSCRIPT
How expensive a logical agent
is?
Logical Agent
Common Sense
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
John McCarthy
• 1955: Develop the phrase
“Artificial Intelligence”
• 1959: Programs with
Common Sense
• 1960: First LISP
implementation
• 1971: Turing Award
Recipient
Intelligent SystemCore Features:
1. Representation of all the behaviors.
2. Interesting changes in behavior must be
expressible in a simple way.
3. All the aspects of behavior must be improvable.
4. Need of partial success concepts.
5. Need to have subroutines which can be
included in procedures as units.
Intelligent SystemCore Features:1. Representation of all the behaviors.
2. Interesting changes in behavior
must be expressible in a simple way.
3. Improving mechanism should be improvable.
4. Need of partial success concepts.
5. The system must be able to create subroutines which can
be included in procedures as units.
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.
Sentence
Imperative SentenceDirect InstructionsEg: “Go to the car and drive
to the airport! “
Declarative SentenceDescription of a situationEg: “I want to go to the
airport”
What is NOT Advice Taker?
• Heuristics are NOT embodied in the
program
• Procedures and heuristics are
described in the language itself
Advice taker• 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.
Some Premises we can make..
A predicate “at”“at(x,y)” is a formalization of “x is at y”
Some rules we can embed..
Deduction• Deduction Process• According to
• x: home, y: desk, z: car• We can deduce
Ambiguities• Semantics of the language Meaning of “at” is controversial• Can have multiple syntactically correct but
semantically incorrect inferences towards the same goal.
Inference algorithms
• Building models (finite models)
• Resolution
• Factoring
Time complexity
• Even an inference algorithm is meant to be sound and complete this may take an exponential time even in well defined finite state environments.
Can we match a logic agent to a human
• We can’t make a generalized inference in a constant time in which most of the human beings are capable of
Thank You!
• Dileepa Fernando• Rashmika Nawaratne
Clarifications ?
The Present…• The symposium on common sense
reasoning held at The Courant Institute – 2001
1. Better sense of how to develop a workable methodology for formalizing common sense
2. How to divide the larger problem up into more manageable parts
Why this subject is difficult?
Simple tasks use implicit assumptions which cannot be determined without proper (deep) study about human mind.
• Real world Example:
• Research paper: