Knowledge Acquisition by an Intelligent Acting Agent Michael Kandefer and Stuart Shapiro Department of Computer Science and Engineering, Center for Cognitive Science, and The National Center for Multisource Information Fusion {mwk3|shapiro}@cse.buffalo.edu Logical Formalizations of Commonsense Reasoning AAAI 2007 Spring Symposia March 28, Stanford University, California
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Knowledge Acquisition by an Intelligent Acting Agent Michael Kandefer and Stuart Shapiro Department of Computer Science and Engineering, Center for Cognitive.
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Knowledge Acquisition by an Intelligent Acting Agent
Michael Kandefer and Stuart ShapiroDepartment of Computer Science and Engineering, Center for Cognitive Science, and The National Center for Multisource
Information Fusion{mwk3|shapiro}@cse.buffalo.edu
Logical Formalizations of Commonsense Reasoning AAAI 2007 Spring Symposia
March 28, Stanford University, California
Outline
• Problem Description and Requirements• Basic algorithm• Example Interactions with Agent• Architecture for agent embodiment (GLAIR)• Symbol anchoring in GLAIR• Solution Details• Conclusions
McCarthy’s Second Telephone Problem
• McCarthy (1979)* presents several problems that require commonsense reasoning.
• Second telephone problem:– A computer program that wants to telephone
someone must reason about who knows the number. More generally, it must reason about what actions will obtain needed knowledge. Knowledge in books and computer files must be treated in a parallel way to knowledge held by persons. [Furthermore, a] program must often determine that it does not know something or that someone else doesn’t.
* McCarthy, J. 1979. First order theories of individual concepts and propositions. In Hayes, J.; Michie, D.; and Mikulich, L., eds., Machine Intelligence 9. Ellis Horwood Ltd. 129-147
Problem Requirements
1. Determining the absence of the requisite knowledge for completing the task at hand.
2. Determining the external information sources that might contain the required information.
3. Knowing how to consult the source(s).4. Retrieving and representing the needed
information.5. Completing the task with the acquired
information.
External Sources
• Text files: – Telephone book:
John 305 Pine Tree Lane 479-2344
– Campus telephone directory:
Bill NSC 678 555-8989
• User is used as an external source– User can type English statements asserting knowledge
– User can enter a phone number when queried by the agent
Basic Calling Procedure
1. Believe none of the information sources have been searched
2. If the individual’s phone number is known, dial it.
3. Otherwise, search each information source that is believed to contain the phone number, dial it if found.
Example Interactions
: What is Mike’s telephone number?
Mike’s telephone number is 555-5612.
: Call Mike.
I am pressing 5. I am pressing 5. I am pressing 5. I am pressing 5. I am pressing 6. I am pressing 1. I am pressing 2.
Example Interactions
: What is Stu’s telephone number?I don’t know.
: Call Stu.Checking Campus Database for Stu’s telephone number.
I am pressing 5. I am pressing 5. I am pressing 5. I am pressing 7. I am pressing 8. I am pressing 9. I am pressing 0.
: What is Stu’s telephone number?Stu’s telephone number is 555-7890.
Example Interactions: What is Albert’s telephone number?
I don’t know.
: Call Albert.Checking Phonebook for Albert’s telephone number...I could not find Albert’s phone number in any external informationsource available to me.
Do you know Albert’s number? Yes
What is Albert’s number (e.g. 555-5555)? 555-1234
I am pressing 5. I am pressing 5. I am pressing 5. I am pressing 1. I am pressing 2. I am pressing 3. I am pressing 4.
: What is Albert’s telephone number?Albert’s telephone number is 555-1234.
GLAIR
• Grounded Layered Architecture with Integrated Reasoning– Architecture for embodied
agents.• Knowledge layer (KL)
– Conscious reasoning– Beliefs, Plans and Policies
• Perceptuo-motor layer (PML)– Primitive actions– Link to embodiment
• Sensory-actuator layer (SAL)– Sensors and actuators
KL
PML
SAL
Implementing the KL
• SNePS-based agents have first-person belief base
• Structured as a set of propositions in a “language of thought” independent of the natural language used to express these beliefs
• SNePSLOG – higher-order logical language interface to SNePS
• bDB - A campus telephone directory• bPB - A telephone directory• n0-n9 - Digits 0-9• b5 – denotes the individual named “Mike”• b10 – denotes the value of Mike’s telephone number.
Thing-denoting Functions
• lex(x) – the thing that can be expressed by the lexeme denoted by x
• compCat(c1,c2) – the complex categorywhich is a subcategory of the category denoted by c2and is modified by c1
Ex. compCat(lex(telephonelex),lex(numberlex))
Telephone Number Values
• N(d,n) - the sequence [d,n]– N(n5,N(n5,N(n5,N(n1,N(n2,N(n3,n4)))))