Transcript What is AI?

CS 531/331: Introduction to AI
Mian Muhammad Awais
Room 416
[email protected]
CS 331: Dr M M Awais (LUMS)
Course Description
Course home page: suraj/lums.edu.pk/~cs331a05
Contacts:lecture notes, tutorials, assignment, grading, office hours, etc.
Textbooks:
1) Luger: Artificial Intelligence: Structures and Strategies for Complex
Problem-solving Fourth Edition (Available as Reading package)
2) S. Russell and P. Norvig Artificial Intelligence: A Modern Approach
Prentice Hall, 2003, First or Second Edition (HANDOUTS)
Grading:
Quizzes (15%)
Lab/Assignments/Project (15%),
Midterm test (30%)
Final exam (40%)
At least 2 Lab Assignments where attendance will be compulsory and
will be taken.
Midterm test (in class) and final exam (as per schedule)
CS 331: Dr M M Awais (LUMS)
TA Support/Office Hours
• Natasha Qureshi (TA)
[email protected]
Office hours (see the website)
• Instructor Office Hours:
3 to 4 PM Every day except Friday
CS 331: Dr M M Awais (LUMS)
Course Outline
• Introduction and Problem Solving
(Today’s Lecture)
• Part I:
Knowledge Representation
• Part II:
Informed Search Methods
• Part III:
Planning / Reasoning/Expert Systems
• Part IV:
Learning
CS 331: Dr M M Awais (LUMS)
Book Chapters
• Book Chapters and articles will be
announced as we go along
• Slides will be available at the website and
the common’s folder
CS 331: Dr M M Awais (LUMS)
Informal Feedback Mechanism
• Every Two Weeks an anonymous
questionnaire will be circulated to evaluate
the course
• Your comments will be welcomed to
improve the course
• We will also have course progress
discussion after every two weeks
CS 331: Dr M M Awais (LUMS)
Questions
CS 331: Dr M M Awais (LUMS)
AI Dimensions
1) Modeling: Thought process/reasoning vs.
behavior/action
2) Evaluation: Success according to human
standards vs. success according to an ideal concept
of intelligence: rationality.
CS 331: Dr M M Awais (LUMS)
What is AI?
Views of AI fall into four categories:
Thinking humanly
Thinking rationally
Acting humanly
Acting rationally
Our Focus is "ACTING RATIONALLY"
CS 331: Dr M M Awais (LUMS)
Acting humanly: Meaning
"Can machines behave like Humans?"
CS 331: Dr M M Awais (LUMS)
Acting humanly: Turing Test
• Turing (1950) "Computing machinery and intelligence":
• Operational test for intelligent behavior: the Imitation Game
• Predicted that by 2000, a machine might have a 30% chance of fooling
a lay person for 5 minutes
• Anticipated all major arguments against AI in following 50 years
• Suggested major components of AI: knowledge, reasoning, language
understanding, learning
•
CS 331: Dr M M Awais (LUMS)
CS 331: Dr M M Awais (LUMS)
Objections :- Turning Test
Most AI Programs Are Not Flexible In Nature
May Not Be Able to Answer Emotional Questions
CS 331: Dr M M Awais (LUMS)
Thinking humanly
“Can machines think like humans”
• Requires scientific theories of internal
activities of the brain
• Cognitive Modeling
CS 331: Dr M M Awais (LUMS)
Thinking humanly: cognitive modeling
•1960s "cognitive revolution": information-processing
psychology
•
•Validation Requires
•Predicting and testing behavior of human subjects
(top-down)
•Direct identification from neurological data
(bottom-up)
•Cognitive Science and Cognitive Neuroscience
•Distinct from AI
•
CS 331: Dr M M Awais (LUMS)
Thinking humanly: Some References
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–
–
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Daniel C. Dennet. Consciousness explained.
M. Posner (edt.) Foundations of cognitive science
Francisco J. Varela et al. The Embodied Mind
J.-P. Dupuy. The mechanization of the mind
CS 331: Dr M M Awais (LUMS)
Thinking rationally
“Laws of Thought”
“Can machines think rationally”
Several Greek schools developed various forms of logic:
notation and rules of derivation for thoughts; may or may
not have proceeded to the idea of mechanization
CS 331: Dr M M Awais (LUMS)
Thinking rationally
Aristotle: what are correct arguments/thought processes?
Mathematics and Philosophy to Modern AI
Problems:
1. Not all intelligent behavior is mediated by logical
deliberation
2. What is the purpose of thinking? What thoughts should I
have?
A reference;

Ivan Bratko, Prolog programming for artificial intelligence.
CS 331: Dr M M Awais (LUMS)
Acting rationally
“Can machines behave rationally”
• Rational behavior: doing the right thing
• The right thing: that which is expected to
maximize goal achievement, given the
available information
• Doesn't necessarily involve thinking – e.g.,
blinking reflex – but thinking should be in
the service of rational action
CS 331: Dr M M Awais (LUMS)
Rational Agents
• An agent is an entity that perceives and acts
• Every thing to be discussed should be taken in the
context of :
RATIONAL AGENTS
• Abstractly, an agent is a function from percept
histories to actions:
[f: P*  A]
• For a given class of environments/tasks, Rational
Agents sought best performance
CS 331: Dr M M Awais (LUMS)
Limitations:Rational Agents
Computational limitations make
perfect rationality unachievable
References
 (this leads to)
Michael Wooldridge.
Reasoning about rational
agents.
Design best program for given
machine resources
CS 331: Dr M M Awais (LUMS)
Definition: AI Systems
Artificial Systems that behave rationally
CS 331: Dr M M Awais (LUMS)
Another Definition: AI?
Computer based solution of complex
problems through the application of
processes that are analogous to the
Human Intelligence
More inclined
towards acting
and thinking
humanly
CONTROVERSIAL ISSUE
(How to define Intelligence)
CS 331: Dr M M Awais (LUMS)
Intelligence
Reasoning
+
- Establishes Relationships
- Perception and Comprehension
- Generalization Ability
Learning
- Memory/Differentiation
Chair vs Table
Spoon vs Fork
Intelligent Beings
Intelligent Systems
CS 331: Dr M M Awais (LUMS)
AI Though Groups
Strong Believers
Weak Believers
CS 331: Dr M M Awais (LUMS)
Weak AI?
Computation
Consciousness
Brain has ingredients that are

Non - computational

Simulating consciousness is not possible
Computational + Non Computational
BRAIN
CS 331: Dr M M Awais (LUMS)
Strong AI ?
Consciousness - “is some complicated computation”
“Computers can achieve or even exceed all Human
Capacities once high computational speeds are achieved”
Brains Are Computers of MEAT?
CS 331: Dr M M Awais (LUMS)
Scope of AI Based Techniques
Main focus
Problems that do not have
algorithmic solutions, or are
very complex
Vague, uncertain and poordefined systems
Systems with decision - making
problems
(Examples?)
CS 331: Dr M M Awais (LUMS)
Example Tasks
Game Playing

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Rules are well defined
algorithmic solutions are very complex
Formalization is easy
Automated Reasoning


Theorem proving
Formal logic/ knowledge representation.
Diagnostic
Knowledge
Expert Systems
Mimic experts such as doctors
Experts
Experts
CS 331: Dr M M Awais (LUMS)
Coding
Natural Language Processing



Computer learn human languages
Machine Translation
Speech Synthesis
Planning And Robotics


Artificial Pets.
Efforts to make “machines”
- Responsive
- Flexible
e.g., Path Planning
CS 331: Dr M M Awais (LUMS)
Human Machine
Summary: AI?
• Innovative Extension of Philosophy:
– Understand and BUILD intelligent entities
• Formal Origin after WWII
• Highly interdisciplinary
• Variety of subfields
– This course will discuss some of them
CS 331: Dr M M Awais (LUMS)
AI prehistory
•
Philosophy
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Mathematics
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Economics
Neuroscience
Psychology
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Computer
engineering
Control theory
•
Linguistics
Logic, methods of reasoning, mind as physical
system foundations of learning, language,
rationality
Formal representation and proof algorithms,
computation, (un)decidability, (in)tractability,
probability
Utility, decision theory
Physical substrate for mental activity
Phenomena of perception and motor control,
experimental techniques
Building fast computers
Design systems that maximize an objective
function over time
Knowledge representation, grammar
CS 331: Dr M M Awais (LUMS)
History of AI
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1943
1950
1956
1952—69
1950s
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1965
1966—73
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1969—79
1980-1986-1987-1995--
McCulloch & Pitts: Boolean circuit model of brain
Turing's "Computing Machinery and Intelligence"
Dartmouth meeting: "Artificial Intelligence" adopted
Look, Ma, no hands!
Early AI programs, including Samuel's checkers
program, Newell & Simon's Logic Theorist,
Gelernter's Geometry Engine
Robinson's complete algorithm for logical reasoning
AI discovers computational complexity
Neural network research almost disappears
Early development of knowledge-based systems
AI becomes an industry
Neural networks return to popularity
AI becomes a science
The emergence of intelligent agents
CS 331: Dr M M Awais (LUMS)
State of the art AI
• Deep Blue defeated the reigning world chess champion
Garry Kasparov in 1997
• Proved a mathematical conjecture (Robbins conjecture)
unsolved for decades
• No hands across America (driving autonomously 98% of
the time from Pittsburgh to San Diego)
• During the 1991 Gulf War, US forces deployed an AI
logistics planning and scheduling program that involved up
to 50,000 vehicles, cargo, and people
• NASA's on-board autonomous planning program
controlled the scheduling of operations for a spacecraft
• Proverb solves crossword puzzles better than most
humans
CS 331: Dr M M Awais (LUMS)
First Reading Assignment
(Write a Two Page Summary on the Scope of AI)
Submission: Email the article to Instructor /TA by Friday
5:00 pm
1. Luger’s
Chapter One: Introduction
Other References:
Alexander Igor’s
Impossible minds
(Help Material Available in the Library)
CS 331: Dr M M Awais (LUMS)
Topics Covered Today
• Luger (Some of the discussion is from Stuart and Norvig)
– Part I
– Chapter 1
– Articles 1.1 to 1.4
• Practice:
– Attempt Exercise Questions
– Especially: Qs 1 to 7, 10 to 12
CS 331: Dr M M Awais (LUMS)