The knowledge-based agent include a knowledge base and an inference system.
A knowledge base is a set of representations of facts of the world.
Each individual representation is called a sentence.
The sentence are expressed in a knowledge representation language.
The agent operates as follows:
- It TELLs the knowledge base what it perceives.
- It ASKs the knowledge base what action it should perform.
- It performs the chosen action.
Architecture of a knowledge-based agent
Knowledge Level.
- The most abstract level: describe agent by saying what it knows.
- Examples: A taxi agent might know that the Golden Gate Bridge connects San Fransisco with the Marin Country.
Logical Level.
- The level at which the knowledge is included into sentences.
- Example: Links (GoldenGateBridge , San Fransisco , MarinCountry.)
Implementation Level.
- The physical representation of the sentence in the logical level.
- Example: (links goldengatebridge sanfrancisco marincountry)
Representing Knowledge
The agent that solve the wumpus world can most effectively be implemented by a knowledge-based approach.
Need to represent states and action, update internal representation, deduce hidden properties and appropriate actions.
Need a formal representation for the KB
And a way to reason about that representation.
Representation , reasoning , and logic
The object of knowledge representation is to express knowledge in a computer-tractable form, so that agents can perform well.
A knowledge representation language is defined by:
- its syntax, which defines all possible sequence of symbols that constitute sentences of the language.
- its semantics, which determines that facts in the world to which the sentence refer.
The connection between sentences and facts
Semantics maps sentences in logic to facts in the world.
The property of one fact following from another is mirrored
by the property of one sentence being entailed by another.
A knowledge base is a set of representations of facts of the world.
Each individual representation is called a sentence.
The sentence are expressed in a knowledge representation language.
The agent operates as follows:
- It TELLs the knowledge base what it perceives.
- It ASKs the knowledge base what action it should perform.
- It performs the chosen action.
Architecture of a knowledge-based agent
Knowledge Level.
- The most abstract level: describe agent by saying what it knows.
- Examples: A taxi agent might know that the Golden Gate Bridge connects San Fransisco with the Marin Country.
Logical Level.
- The level at which the knowledge is included into sentences.
- Example: Links (GoldenGateBridge , San Fransisco , MarinCountry.)
Implementation Level.
- The physical representation of the sentence in the logical level.
- Example: (links goldengatebridge sanfrancisco marincountry)
Representing Knowledge
The agent that solve the wumpus world can most effectively be implemented by a knowledge-based approach.
Need to represent states and action, update internal representation, deduce hidden properties and appropriate actions.
Need a formal representation for the KB
And a way to reason about that representation.
Representation , reasoning , and logic
The object of knowledge representation is to express knowledge in a computer-tractable form, so that agents can perform well.
A knowledge representation language is defined by:
- its syntax, which defines all possible sequence of symbols that constitute sentences of the language.
- its semantics, which determines that facts in the world to which the sentence refer.
The connection between sentences and facts
Semantics maps sentences in logic to facts in the world.
The property of one fact following from another is mirrored
by the property of one sentence being entailed by another.
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