This document introduces artificial intelligence and the goals of creating intelligent entities that can perform both mundane and expert tasks. It discusses using Prolog, a programming language based on logic, to represent knowledge about the world through facts and rules. Prolog finds answers to questions by performing a depth-first search through the knowledge base to identify all possible solutions through reasoning and backtracking. The document also outlines upcoming labs that will provide hands-on experience using Prolog and another AI language called NetLogo.
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.