CSE4/563: Knowledge RepresentationRecitation September 13, 2010

“Intelligence is the art of good guesswork.” –H.B. Barlow

Questions/Concerns

http://www.cse.buffalo.edu/~shapiro/Courses/CSE563/2010/Homeworks/hw0.pdf

What is Artificial Intelligence?

What is Artificial Intelligence?

• What kinds of things or concepts do we need in the definition?

What is Artificial Intelligence?

"[The automation of] activities that we associate with human thinking, activities such as decision-making, problem solving, learning..." (Bellman, 1978)

"The study of mental faculties through the use of computational models" (Charniac and McDermott, 1985)

"The study of the computations that make it possible to percieve, reason, and act" (Winston, 1992)

What is Artificial Intelligence?

"The art of creating machines that perform functions that require intelligence when performed by people" (Kurzweil, 1990)

"The study of how to make computers do things which at the moment people are currently better" (Rich and Knight, 1991)

"Computational Intelligence is the study of the design of intelligent agents" (Poole, et al, 1998)

"AI... is concerned with intelligent behavior in artifacts" (Nilsson, 1998)

What is Artificial Intelligence?

A field of computer science and engineeringconcerned with the computationalunderstanding of what is commonly calledintelligent behavior, and with the creation ofartifacts that exhibit such behavior. (Shapiro, 2010)

Propositions

• What are they?

Propositions

• What are they?

• “I believe that it is not the case that…”

• Examples

• Counter-examples

Semantics

• Intensional

Semantics

• Intensional– Independent of model or situation– Represented in English

• Extensional

Semantics

• Intensional– Independent of model or situation– Represented in English

• Extensional– AKA ‘Denotation’– Relative to model or situation– Resolves to a truth value

Example

[Betty is the Passenger <=> ~Betty is the Driver]What are the intensional semantics?

Example

[Betty is the Passenger <=> ~Betty is the Driver]What are the intensional semantics?Betty is the passenger if and only if Betty is not

the driver.

What are the extensional semantics?

Example

Betty is the Passenger <=> ~Betty is the DriverWhat are the intensional semantics?Betty is the passenger if and only if Betty is not

the driver.

What are the extensional semantics?…is true if [[Betty is the Passenger]] and [[~Betty

is the driver]] are both true or both false, otherwise it is false.

Model Finding with Excel

Betty is the Passenger <=> ~Betty is the DriverTom is the Passenger <=> ~Tom is the DriverBetty is the Passenger <=> Tom is the DriverTom is the Passenger <=> Betty is the Driver

~Betty is the Passenger.

Model Finding with Semantic Tableau

T:Betty is the Passenger <=> ~Betty is the DriverT:Tom is the Passenger <=> ~Tom is the DriverT:Betty is the Passenger <=> Tom is the DriverT:Tom is the Passenger <=> Betty is the Driver

F:~Betty is the Driver.