Download Introduction to Artificial Intelligence

Princess Nora University
Artificial Intelligence
CS 370
Level 5
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Chapter 1: Introduction
Included Topics :
• What is AI ?
• Applied Areas of AI.
• What’s involved in Intelligence?
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Recommended Books:
1. “Artificial Intelligence: A modern
approach” Stuart Russell, Peter Norvig,
Prentice Hall, 2003 (new edition 2006)
2. “Artificial Intelligence In Perspective”, by
Daniel G. Bobrow.
3. Artificial Intelligence :A Guide to Intelligent
Systems , MICHAEL NEGNEVITSKY, 2nd
Edition.
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What is AI ? (1)
• "The exciting new effort to make computers
think . . . machines with minds, in the full
and literal sense" (Haugeland, 1985)
• "[The automation of] activities that we
associate with human thinking, activities
such as decision-making, problem solving,
learning
.."(Bellman, 1978)
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What is AI ? (2)
• "A field of study that seeks to explain and
emulate intelligent behavior in terms of
computational processes" (Schalkoff, 1 990)
• "The branch of computer science that is concerned
with the automation of intelligent behavior" (Luger
and Stubblefield, 1993)
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What is AI ? (3)
Artificial Intelligence :
is a science that has defined its goal as
making machines do things that would
require intelligence if done by humans.
Intelligence : is ability to learn and
understand to solve problems and to
make decisions.
A machine is thought intelligent if it can
achieve human level performance in
some cognitive task.
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What is AI ? (4)
Views of AI fall into four categories:
Systems that think like humans.
Systems that think rationally.
Systems that act like humans.
Systems that act rationally.
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Thinking humanly (1)
The way in which the computer carries out the
tasks is important.
• Cognitive Science → theories that study the
way human would think . The
interdisciplinary field of cognitive science
brings together computer models from AI and
experimental techniques from psychology to
try to construct precise and testable theories of
the workings of the human mind.
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Thinking humanly (2)
• Cognitive Science approach
– Try to get “inside” our minds
– E.g., conduct experiments with people to try to
“reverse-engineer” how we reason, learning,
remember, predict
• Problems
– Humans don’t behave rationally . e.g., insurance
– The reverse engineering is very hard to do
– The brain’s hardware is very different to a
computer program
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Acting Humanly: The Turing Test (1)
Turing (1950) was interested in the following
question: Can machines think?
But he immediately decides that answering this
question directly is hopeless.
The Element of the Turing Test Are :
• An interrogator (a person who will ask
questions)
• a computer (intelligent machine !!)
• A person who will answer to questions
• A curtain (separator)
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Acting Humanly: The Turing Test (2)
• Typed input/output only
• Any kind of question is fair.
• The player poses questions to the
computer /other human.
• Can the player reliably distinguish the computer from
the human?
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Acting Humanly: The Turing Test (3)
• Suggested major components of AI: knowledge, reasoning,
language understanding, learning
• The computer would need to possess some capabilities:
• Natural language processing: To communicate
successfully.
• Knowledge representation: To store what it knows or
hears.
• Automated reasoning: to answer questions and draw
conclusions using stored information.
• Machine learning: To adapt to new circumstances and
to detect and extrapolate patterns.
• Computer vision: To perceive objects.
• Robotics to manipulate objects and move.
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Passing The Turing Test
• A computer passes the Turing test if
interrogators can not distinguish the
machine from human on the basis of the
answers to their questions.
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Thinking rationally: "laws of thought"
• Represent facts about the world via logic.
• Use logical inference as a basis for reasoning about
these facts.
• Can be a very useful approach to AI
– E.g., theorem-provers
Limitations
1.
2.
Not all intelligent behavior is mediated by logical
deliberation.
What is the purpose of thinking? What thoughts
should I have?
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Acting rationally : rational agent approach(1)
Rational behavior: doing the right thing.
The right thing: that which is expected to
maximize goal achievement, given the
available information.
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Acting rationally : rational agent approach(2)
• Advantages:
- More general than the “laws of thought”
approach.
- More amenable to scientific development
than human-based approaches.
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Applied Areas of AI
•
•
•
•
•
•
Game playing
Speech and language processing
Expert reasoning
Planning and scheduling
Vision
Robotics
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Some Examples
• Playing chess
• Driving on the highway
• Translating languages
• Recognizing speech
• Diagnosing diseases
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Playing Chess
• Environment?
– Board
• Actions?
– Legal moves
• Doing the right thing?
– Moves that lead to wins
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Recognizing Speech
• Environment
– Audio signal
– Knowledge of user
• Actions
– Choosing word sequences
• Doing the right thing
– Recovering the users words
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Diagnosing Diseases
• Environment
– Patient information
– Results of tests
• Actions
– Choosing diseases
– Choosing treatments
• Doing the right thing
– Eliminating disease
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Translation
• Environment
– Source text to be translated
• Actions
– Word sequences in target language
• Doing the right thing?
– Words that achieve the same effect
– Words that are faithful to the source
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Driving
• Environment
– Restricted access highway
• Actions
– Accelerate, turn, navigate, other controls
• Doing the right thing
– Stay safe, get where you want to go, get there
quickly
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What’s involved in Intelligence?
• Ability to interact with the real world
– to perceive, understand, and act
– e.g., speech recognition and understanding and synthesis
– e.g., image understanding
– e.g., ability to take actions, have an effect
• Reasoning and Planning
– modeling the external world, given input
– solving new problems, planning, and making decisions
– ability to deal with unexpected problems, uncertainties
• Learning and Adaptation
– we are continuously learning and adapting
– our internal models are always being “updated”
• e.g., a baby learning to categorize and recognize animals
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