Transcript Artificial Intelligence

Artificial Intelligence
What is it ?
Some Definitions
• Herbert Simon: We call programs intelligent if
they exhibit behaviors that would be regarded
intelligent if they were exhibited by human
beings.
• Elaine Rich: AI is the study of techniques for
solving exponentially hard problems in
polynomial time by exploiting knowledge about
the problem domain.
• Elaine Rich and Kevin Knight: AI is the study
of how to make computers do things at which, at
the moment, people are better.
More
• Stuart Russell and Peter Norvig: [AI] has to do with
smart programs, so let's get on and write some.
• Avron Barr and Edward Feigenbaum: Physicists ask
what kind of place this universe is and seek to
characterize its behavior systematically. Biologists ask
what it means for a physical system to be living. We in AI
wonder what kind of information-processing system can
ask such questions.
• Claudson Bornstein: AI is the science of common
sense.
• Douglas Baker: AI is the attempt to make computers do
what people think computers cannot do.
• Astro Teller: AI is the attempt to make computers do
what they do in the movies.
More
•
The goal of work in artificial intelligence is to build machines that
perform tasks normally requiring human intelligence. (Nilsson,
Nils J. (1971), Problem-Solving Methods in Artificial Intelligence
(New York: McGraw-Hill): vii.)
•
Research scientists in Artificial Intelligence try to get machines to
exhibit behavior that we call intelligent behavior when we observe
it in human beings. (Slagle, James R. (1971), Artificial
Intelligence: The Heuristic Programming Approach (New York:
McGraw-Hill): 1.)
•
B. Raphael ... has suggested that AI is a collective name for
problems which we do not yet know how to solve properly by
computer. (Michie, Donald, "Formation and Execution of Plans by
Machine," in N. V. Findler & B. Meltzer (eds.) (1971), Artificial
Intelligence and Heuristic Programming (New York: American
Elsevier): 101-124; quotation on p. 101.)
Even More
1. What is or should be [AI researchers']
main scientific activity--studying the
structure of information and the structure
of problem solving processes
independently of applications and
independently of its realization in animals
or humans. (McCarthy, John (1974),
Review of "Artificial Intelligence: A
General Survey," Artificial Intelligence 5:
317-322; quotation on p. 317.)
More
1. Artificial intelligence is concerned with
the attempt to develop complex
computer programs that will be capable
of performing difficult cognitive tasks.
(Eysenck, Michael W. (1990), "Artificial
Intelligence," in M.W. Eysenck (ed.), The
Blackwell Dictionary of Cognitive
Psychology (Oxford: Basil Blackwell):
22.)
And Your Definition?
• What do you think AI is in your own words.
From last weeks discussion
• We know AI has something to do with
problem solving
• It involves Knowledge
• Reasoning and Learning and much much
more.
Obviously the next Question is
• WHAT is Knowledge???????????
Knowledge
• Eolas
• Is it Data
• Is it Information
• Is it something else
What do you think?
Data
• Data, are basic facts
– typically found in a
database.
Name
Age
Car
John
21
Mini
Data
• Turban and Aronson definition
• “Data are a collection of facts,
measurements and statistics.”
Information
• Information includes data
• But also includes associations ,
relationships, semantics and so on
Information
• Turban and Aronson definition
• “Information is defined as organized or
processed data that are timely (i.e.
inferences from the data are drawn within
the time frame of applicability”
Knowledge
• ????????????????????
What is knowledge ?
• • What do people have inside their head when they know something
?
• • Is knowledge expressed in words ?
• • If so, how could one know things that are easier to do than to say,
like
• tying a shoestring or hitting a baseball ?
• • If knowledge is not expressed in words, how can it be transmitted
in
• language ?
• • How is knowledge related to the world ?
• • What are the relationships between the external world, knowledge
• in the head, and the language used to express knowledge about the
• world ?
• Knowledge is more than a static encoding of
facts, it also includes the ability to use those
facts in interacting with the world.
• Basic premise of AI is that knowledge of
something is the ability to form a mental model
that accurately represents the thing as well as
the actions than can be performed by it and on
it.
• By testing actions on the model, a person (or
robot) can predict what is likely to happen in the
real world.
Knowledge
• knowledge is information that can be
applied for a specific and useful purpose
• Knowledge is that which we know.
• Knowledge – Facts – ConceptsProcedures- How- To – AssociationsAnalogy-Rules of Thumb-ObjectsClassifications-Meta KnowledgeSomething to be learned
Definitions of Knowledge
“Dictionary Definition”
• The state or fact of knowing.
• Familiarity, awareness, or understanding
gained through experience or study.
• The sum or range of what has been
perceived, discovered, or learned.
More of the definition
• Learning; erudition: teachers of great
knowledge.
• Specific information about something.
• Carnal knowledge.
Physical Symbol Hypothesis of
Knowledge
• The prevailing epistemology is the physical
symbol hypothesis of Newell and Simon (1981).
• Essentially this hypothesis considers that
knowledge consists of symbols of reality and
relationships between these symbols and that
intelligence is the appropriate logical
manipulation of the symbols and their relations.
• Although Newell an Simon developed these
ideas in the 50's as a basis for AI, they have a
long and time honoured philosophical ancestry,
through the early Wittgenstein, back through
Descartes to Plato with his archetypes.
Knowledge Principle
• The extension of the physical symbol
hypothesis is the "knowledge principle",
that is, the success of an expert system
does not depend on the sophistication of
its inferencing or reasoning strategy, but
on the amount of information it contains on
how symbols are interrelated, that is the
amount of knowledge it contains.
(Feigenbaum 1977).
Many Definitions
• WIPO Secretariat made use of the
following working concept of ‘traditional
knowledge’ for the purposes of the factfinding missions in1998-1999:
‘traditional knowledge’ … refer[s] to tradition
based literary, artistic or scientific works;
performances; inventions; scientific
discoveries; designs; marks, names and
symbols; undisclosed information; and all
other tradition-based innovations and
creations resulting from intellectual activity in
the industrial, scientific, literary or artistic
fields. “
Big Issue
• How do we get Knowledge into a
computer
• Knowledge Representation
• And
• How do we use it then - Inference
Fundamental System Issues
• A robust AI system must be able to store
knowledge, apply that knowledge to the solution
of problems, and acquire new knowledge
through experience.
• Among the challenges that face researchers in
building AI systems, there are three that are
fundamental:
• knowledge representation, reasoning and
searching, and learning.