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Artificial Intelligence
Introduction
   Alison Cawsey
   room: G36
   email: alison@macs.hw.ac.uk

   Ruth Aylett
   Room: 1.37
   Email: ruth@macs.hw.ac.uk
What is AI?
s   Various definitions:
    x Building intelligent entities.
    x Getting computers to do tasks which require
      human intelligence.
s   But what is intelligence?
s   Simple things turn out to be the hardest to
    automate:
    x Recognising a face.
    x Navigating a busy street.
    x Understanding what someone says.
s   All tasks require reasoning on knowledge.
Why do AI?
s   Two main goals of AI:
    x To understand human intelligence better. We
      test theories of human intelligence by writing
      programs which emulate it.
    x To create useful smart programs able to do
      tasks that would normally require a human
      expert.
Who does AI?
 s   Many disciplines contribute to goal of
     creating/modelling intelligent entities:
     x Computer Science
     x Psychology (human reasoning)
     x Philosophy (nature of belief, rationality, etc)
     x Linguistics (structure and meaning of
       language)
     x Human Biology (how brain works)
 s   Subject draws on ideas from each discipline.
Typical AI Problems
s   Intelligent entities (or agents) need to be able to do
    both mundane and expert tasks:
s   Mundane tasks - consider going shopping:
    x Planning a route, and sequence of shops to visit!
    x Recognising (through vision) buses, people.
    x Communicating (through natural language).
    x Navigating round obstacles on the street, and
      manipulating objects for purchase.
s   Expert tasks are things like:
    x medical diagnosis.
    x equipment repair.
s   Often mundane tasks are the hardest.
Philosophical Issues
s What is intelligence?
s Can a machine be truly intelligent? Is there more to

  human intelligence than rules, data and calculations?
Tests:
s Turing Test: Can someone tell which is the machine,

  when communicating to human and to a machine in
  another room? If not, can we call the machine
  intelligent?
s Chinese room: Searle says no. Describes a thought

  experiment where talk in Chinese by looking up what
  to say from huge rule book.
s Loebner contest: Contest for most human-like

  conversation system.
Example conversation with system
winning Loebner prize
s P: No worries! Hey! I didnt come here to be subjected to
  bad language! How rude!
s J: Sorry, sorry. Didnt mean to offend. So, how old are

  you?
s P: Thats OK. Just dont do it again. Well, should my age

  really matter. Just for the record Im 24. How old are you
  then.
But.. System was based on fairly simple methods, with pre-
  stored amusing replies. These simple methods first used
  in Eliza - a program to emulate psychotherapist.
    Try esc-x doctor while in emacs for a version of Eliza.
s   Human-like performance doesnt guarantee intelligence.
About this Module
Covers following AI topics
  x AI Programming, using Prolog.
  x Knowledge representation:
       3   How do we represent knowledge about the world in
           a formal manner that can be manipulated in a sound
           and efficient manner?
  x   Search:
       3   How can an AI system go through all the possibilities
           in a systematic manner when looking for solutions to
            complex problems.
About this Module
  x   Natural Language:
       3   How can a system communicate in a natural
           language such as English.
  x   Machine learning and neural networks:
       3   How can a system learn from experience, or
           from past case data.
  x   Agents:
       3   How can we develop and use practical
           intelligent agents.
  x   Knowledge Engineering:
       3   How do we elicit the human expertise required
           to build intelligent applications.
Labs and Coursework
 s   Weekly lab, starting Wed 16th April!
 s   Labs give you experience of two AI programming
     languages: Prolog and NetLogo.
 s   Weeks 1-4: Exercises on AI Programming in
     Prolog.
     x   Some of these must be ticked off by Lab
         demonstrators and will contribute to your
         coursework mark.
 s   Weeks 5-8: NetLogo with assessed exercise.
Books etc.
s   Essence of Artificial Intelligence by Alison
    Cawsey, Prentice Hall.
    x   Review: I missed most of the lectures but thanks to this short
        and sweet book I passed my first year introduction to AI course.
        If you are a slack student taking an AI course - buy this book. 
s   Artificial Intelligence: A Modern Approach (second
    edition), Russell & Norvig, Prentice Hall. 2003
s   Artificial Intelligence: Structures and Strategies for
    Complex Problem Solving, Luger, Benjamin Cummings.
s   際際滷s, lab exercises etc for weeks 1-4 on
    www.macs.hw.ac.uk/~alison/ai3/
Module prerequisites/assumptions
  s   Programming (software engineering).
  s   CS students will benefit from:
      x   Logic and Proof
  s   IT students will benefit from
      x   Cognitive Science.
  s   Relevant material from logic and proof will be
      reviewed again for benefit of IT students.
Getting Started with Prolog
s   Prolog is a language based on first order
    predicate logic. (Will revise/introduce this later).
s   We can assert some facts and some rules, then
    ask questions to find out what is true.
s   Facts: likes(john, mary).
            tall(john).
            tall(sue).
            short(fred).
            teaches(alison, artificialIntelligence).
s   Note: lower case letters, full stop at end.
Prolog
s   Rules:
        likes(fred, X) :- tall(X).
        examines(Person, Course) :- teaches(Person, Course).


    x John likes someone if that someone is tall.
    x A person examines a course if they teach that
      course.
    x NOTE: :- used to mean IF. Meant to look a bit
      like a backwards arrow
    x NOTE: Use of capitals (or words starting with
      capitals) for variables.
Prolog
s   Your program consists of a file containing
    facts and rules.
s   You run your program by asking questions
    at the prolog prompt.

          |?- likes(fred, X).

s   John likes who?
s   Answers are then displayed. Type ; to get
    more answers: (Note: darker font for system output)
          X = john ? ;
          X = sue ? ;
          no
Prolog and Search
s   Prolog can return more than one answer to a
    question.
s   It has a built in search method for going
    through all the possible rules and facts to
    obtain all possible answers.
s   Search method depth first search with
    backtracking.
Summary
s   AI about creating intelligent entities, with a
    range of abilities such as language, vision,
    manipulation/navigation..
s   Intelligence involves knowledge - this must be
    represented with and reasoned with.
s   Solving problems involves search.
s   Prolog is a language geared to representing
    knowledge and searching for solutions.
s   Prolog programs based on facts and rules, and
    run by asking questions.

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  • 1. Artificial Intelligence Introduction Alison Cawsey room: G36 email: alison@macs.hw.ac.uk Ruth Aylett Room: 1.37 Email: ruth@macs.hw.ac.uk
  • 2. What is AI? s Various definitions: x Building intelligent entities. x Getting computers to do tasks which require human intelligence. s But what is intelligence? s Simple things turn out to be the hardest to automate: x Recognising a face. x Navigating a busy street. x Understanding what someone says. s All tasks require reasoning on knowledge.
  • 3. Why do AI? s Two main goals of AI: x To understand human intelligence better. We test theories of human intelligence by writing programs which emulate it. x To create useful smart programs able to do tasks that would normally require a human expert.
  • 4. Who does AI? s Many disciplines contribute to goal of creating/modelling intelligent entities: x Computer Science x Psychology (human reasoning) x Philosophy (nature of belief, rationality, etc) x Linguistics (structure and meaning of language) x Human Biology (how brain works) s Subject draws on ideas from each discipline.
  • 5. Typical AI Problems s Intelligent entities (or agents) need to be able to do both mundane and expert tasks: s Mundane tasks - consider going shopping: x Planning a route, and sequence of shops to visit! x Recognising (through vision) buses, people. x Communicating (through natural language). x Navigating round obstacles on the street, and manipulating objects for purchase. s Expert tasks are things like: x medical diagnosis. x equipment repair. s Often mundane tasks are the hardest.
  • 6. Philosophical Issues s What is intelligence? s Can a machine be truly intelligent? Is there more to human intelligence than rules, data and calculations? Tests: s Turing Test: Can someone tell which is the machine, when communicating to human and to a machine in another room? If not, can we call the machine intelligent? s Chinese room: Searle says no. Describes a thought experiment where talk in Chinese by looking up what to say from huge rule book. s Loebner contest: Contest for most human-like conversation system.
  • 7. Example conversation with system winning Loebner prize s P: No worries! Hey! I didnt come here to be subjected to bad language! How rude! s J: Sorry, sorry. Didnt mean to offend. So, how old are you? s P: Thats OK. Just dont do it again. Well, should my age really matter. Just for the record Im 24. How old are you then. But.. System was based on fairly simple methods, with pre- stored amusing replies. These simple methods first used in Eliza - a program to emulate psychotherapist. Try esc-x doctor while in emacs for a version of Eliza. s Human-like performance doesnt guarantee intelligence.
  • 8. About this Module Covers following AI topics x AI Programming, using Prolog. x Knowledge representation: 3 How do we represent knowledge about the world in a formal manner that can be manipulated in a sound and efficient manner? x Search: 3 How can an AI system go through all the possibilities in a systematic manner when looking for solutions to complex problems.
  • 9. About this Module x Natural Language: 3 How can a system communicate in a natural language such as English. x Machine learning and neural networks: 3 How can a system learn from experience, or from past case data. x Agents: 3 How can we develop and use practical intelligent agents. x Knowledge Engineering: 3 How do we elicit the human expertise required to build intelligent applications.
  • 10. Labs and Coursework s Weekly lab, starting Wed 16th April! s Labs give you experience of two AI programming languages: Prolog and NetLogo. s Weeks 1-4: Exercises on AI Programming in Prolog. x Some of these must be ticked off by Lab demonstrators and will contribute to your coursework mark. s Weeks 5-8: NetLogo with assessed exercise.
  • 11. Books etc. s Essence of Artificial Intelligence by Alison Cawsey, Prentice Hall. x Review: I missed most of the lectures but thanks to this short and sweet book I passed my first year introduction to AI course. If you are a slack student taking an AI course - buy this book. s Artificial Intelligence: A Modern Approach (second edition), Russell & Norvig, Prentice Hall. 2003 s Artificial Intelligence: Structures and Strategies for Complex Problem Solving, Luger, Benjamin Cummings. s 際際滷s, lab exercises etc for weeks 1-4 on www.macs.hw.ac.uk/~alison/ai3/
  • 12. Module prerequisites/assumptions s Programming (software engineering). s CS students will benefit from: x Logic and Proof s IT students will benefit from x Cognitive Science. s Relevant material from logic and proof will be reviewed again for benefit of IT students.
  • 13. Getting Started with Prolog s Prolog is a language based on first order predicate logic. (Will revise/introduce this later). s We can assert some facts and some rules, then ask questions to find out what is true. s Facts: likes(john, mary). tall(john). tall(sue). short(fred). teaches(alison, artificialIntelligence). s Note: lower case letters, full stop at end.
  • 14. Prolog s Rules: likes(fred, X) :- tall(X). examines(Person, Course) :- teaches(Person, Course). x John likes someone if that someone is tall. x A person examines a course if they teach that course. x NOTE: :- used to mean IF. Meant to look a bit like a backwards arrow x NOTE: Use of capitals (or words starting with capitals) for variables.
  • 15. Prolog s Your program consists of a file containing facts and rules. s You run your program by asking questions at the prolog prompt. |?- likes(fred, X). s John likes who? s Answers are then displayed. Type ; to get more answers: (Note: darker font for system output) X = john ? ; X = sue ? ; no
  • 16. Prolog and Search s Prolog can return more than one answer to a question. s It has a built in search method for going through all the possible rules and facts to obtain all possible answers. s Search method depth first search with backtracking.
  • 17. Summary s AI about creating intelligent entities, with a range of abilities such as language, vision, manipulation/navigation.. s Intelligence involves knowledge - this must be represented with and reasoned with. s Solving problems involves search. s Prolog is a language geared to representing knowledge and searching for solutions. s Prolog programs based on facts and rules, and run by asking questions.