Basic Questions

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Basic Questions

• What is intelligence?
• Is it natural category? Is it always
  characterized by a common set of properties?
• Can it be described by a set of abstract laws?
• Can intelligence exist outside the human mind?

IntroductionBasic Questions
2
What is Intelligence?

• How is intelligence measured?
• Can it be defined without relating it to human
  intelligence?
• Is intelligence a process or knowledge?
• Is intentionality a necessary component?

IntroductionWhat is Intelligence?
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Measuring Intelligence

• Duplicate or simulate human intelligence
• Is all measurement subjective, depending on the
  assumption of goals?
• Problem of intentionality
• If it behaves as if it understands can we assume
  it understands? What is understanding?
• Turing test strictly behavioral

IntroductionMeasuring Intelligence
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Study of the Mind
From Franklin,Artificial Minds
Top Down
Psychology
Artificial Intelligence
Analytic
Synthetic
MIND
Neuroscience
Mechanism of mind
Bottom Up
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What is AI?
From RussellNovig(2003),AI, A Modern Approach,
Prentice Hall
IntroductionWhat is AI?
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Theory of Computability

• Church Thesis Any procedure that can be
  described explicitly can be computed with
  recursive functions.
• Turings view framed in terms of a class of
  automata, Turing machines.
• Thesis claims computable process can be
  programmed, i.e. is equivalent or less powerful
  than a Turing machine.

IntroductionTheory of Computability
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Recursive Functions

• There is some method of computing three things
• 1. The zero function which will yield a value of
  zero given any input of natural
  numbers(0,1,2,3..)
• 2. The successor function that yields the number
  that follows any natural number
• 3. The set of identity functions that given the
  input of string of input arguments returns the
  identical value of one of them as specified by
  its position in the string

IntroductionRecursive Functions
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Recursive Functions (continued)

• There is a rote procedure for determining in a
  finite time, the output of a function.
• There is a finite set of operations that can be
  applied to a given input and applied again to the
  successive result to yield the functions output
  in a finite time
• Describes what is meant by an algorithmic
  solution, equivalent to a Turing machine

IntroductionRecursive Functions(continued)
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Doctrine of Functionalism

• Presented by Cambridge psychologist Kenneth Craik
  in The Nature of Explanation
• States that the human mind translates aspects of
  the external world into internal representations,
  processes these representations and translates
  these representation back into behavior
• Mental processes are essentially computations
  that manipulate and interpret representations of
  the world

IntroductionDoctrine of Functionalism
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Can the Mind be Programmed?
Is the mind explainable?
no
yes
There IS a ghost in the machine!
Is the Church/Turing Thesis correct?
no
yes
The mind may depend on something noncomputable
Is functionalism correct?
no
yes
The mind can be modeled
The mind is computable
IntroductionCan the Mind be Programmed?
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The Nay Sayers

• John Searle says the idea of a non-biological
  machine being intelligent is incoherent.
• Hubert Dreyfus says that AI is impossible because
  world of the subjective is more important than
  world of the objective
• Joseph Weizenbaum says the idea is obscene,
  anti-human and immoral.

IntroductionThe Nay Sayers
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Alan Turing (1912-1954)

• Born in London to family employed in the Indian
  Civil Service
• Found school an almost incomprehensible
  experience
• Devastated by death of best friend, Christopher
  Morcom

Alan Turing Early Life
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Alan Turing Decidability

• As an undergraduate at Kings College Cambridge,
  working on probability theory, became interested
  in question of decidability
• Given a mathematical proposition can an algorithm
  be found which will decide if it is true or false

Alan Turing Decidability
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Alan Turing Turing Machine

• Expressed his results in a theoretical machine,
  the Turing machine
• Alonzo Churchs paper published first in 1936
• His contribution was link between logical
  instructions, action of the mind and a machine

Alan Turing Turing Machine
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Alan Turing Code Breaker

• Turing took up full-time work at the wartime
  cryptanalytic headquarters, Bletchley Park
• Enigma methods used in German Naval
  communications were generally regarded as
  unbreakable, but Turing cracked the system at the
  end of 1939
• He planned the embodiment of the Universal Turing
  Machine in electronic form, or in effect,
  invented the digital computer

Alan Turing Code Breaker
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Alan TuringFounder of Computer Science

• Turing was almost uniquely in possession of three
  key ideas
• his own 1936 concept of the universal machine
• the potential speed and reliability of electronic
  technology
• the inefficiency in designing different machines
  for different logical processes.

Alan Turing Founder of Computer Science
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Alan Turing Turing Test

• Computing Machinery and Intelligence appeared in
  Mind 1950
• Turing's reasoning was that, assuming
  intelligence could only be determined
  behaviorally, then any agent that behaved like an
  intelligent agent was intelligent
• Conversation was the key to judging intelligence.
  

Alan Turing Turing Test
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Turing Test Requirements

• Natural language processing
• Knowledge representation to store what it knows
• Automated reasoning to use the stored information
  to answer questions
• Machine learning to adapt to new circumstances

Alan Turing Turing Test
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Turing Test
Interrogator The first line of the sonnet reads
"How shall I compare thee to as summer's day".
Would not a spring's day" do just as
well? Witness It wouldn't scan Interrogator
How about "a winter's day". That would scan all
right. Witness Yes, but nobody would like to be
compared to a winter's day. Interrogator Would
you say Mr..Pickwick reminded you of
Christmas? Witness In a way. Interrogator Yet
Christmas is a winter's day and I doubt that Mr..
Pickwick would mind the comparison. Witness I
don't think you are being serious. By a winter's
day one means a typical winter's day, not a
special one like Christmas.
IntroductionTuring test
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Turing TestObjection 1

• "The Theological Objection" God created every
  man and woman and gave them a soul - but did not
  do the same for machines or animals.
• Turing dismisses this idea as out of hand, and
  refutes the objection by showing that different
  religions have different beliefs. Moslems for
  example believe that women have no souls.

Turing TestObjection 1
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Turing TestObjection 2

• 2 "The 'Heads in the Sand' Objection" The
  thought of machines that have intelligence is too
  dreadful to even think about.
• Turing asks why we think that Man is superior to
  the rest of creation, but does not spend any time
  in his paper refuting the argument, instead
  dismissing it out of hand.

Turing TestObjection 2
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Turing TestObjection 3

• 3 "The Mathematical Objection" This rather
  abstract argument involves a machine of infinite
  capacity. It is claimed by some mathematicians
  (Godel, Church, Rosser and Turing himself) that
  there will always be some questions that the
  computer simply cannot answer.
• Turing's refutes this by asking why humans cannot
  have certain questions that are unanswerable.

Turing TestObjection 3
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Turing TestObjection 4

• 4 "The Argument from Consciousness" 'Not until
  a machine can write a sonnet or compose a
  concerto because of thoughts and emotions felt,
  could we agree that machine equals brain.
• This argument renders the Turing test somewhat
  ineffective because testing for creativity via a
  terminal is restrictive in many ways. He also
  argues there is no way to test for consciousness.
  It is only possible to be certain of one's own
  consciousness.

Turing TestObjection 4
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Turing TestObjection 5

• 5 "Arguments from Various Disabilities"
  Although machines can undoubtedly do many things
  that may appear to be intelligent, they can
  never 'Be kind, beautiful, friendly, have
  initiative, have a sense of humor, tell right
  from wrong, make mistakes, fall in love, enjoy
  strawberries and cream...', etc.
• Turing claims that one day machines may be able
  to complete such tasks, but at the moment
  sufficient research into why man has such
  capabilities has yet to be undertaken.

Turing TestObjection 5
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Turing TestObjection 6

• 6 "Lady Lovelace's Objection" Computers can do
  only what they are told.
• Turing argues that one day it may be possible to
  construct electronic equipment that will 'think
  for itself'. He then argues that perhaps no-one
  can think of 'new' things, in other words,
  everything we think is generated from what we
  already know - we are simply adapting it.

Turing TestObjection 6
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Turing TestObjection 7

• 7 "Argument from Continuity in the Nervous
  System" The nervous system is clearly different
  from a computer in the way it works at neuron
  level. The will never be modeled by a computer.
• The way in which the machine/human operates is
  not visible to the interrogator, and - according
  to Turing - the same results should, one day, be
  obtainable.

Turing TestObjection 7
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Turing TestObjection 8

• 8 "The Argument from Informality of Behavior"
  It is impossible to model the behavior of humans
  because there is so much variation from man to
  man.
• Turing argues that it is perfectly possible for a
  computer to produce output from a certain input
  that would be impossible to predict without many
  1000s of years of observation. Who is to say
  that, with an equal amount of observation, the
  behavior of humans does not become predictable.

Turing TestObjection 8
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Turing TestObjection 9

• 9 The Argument from Extra-Sensory Perception It
  involves a human using ESP to do tasks such as
  guessing the suit of a card that the interrogator
  is holding. By using ESP, they will be able
  (according to Turing) to get statistically more
  guesses correct than the computer. Turing claims
  that the evidence for telepathy is
  'overwhelming'.
• Turing suggests that the competitors should be
  placed in a 'telepathy-proof room'.

Turing Test Objection 9
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Turing Test Loebner Prize

• 1991 tournament billed as the first actual
  administration of the Turing test
• Added two rules
• Limiting the topic.
• Limiting the tenor (no trickery or guile)
• 10 contestants 6 computers and 4 humans
• Won by Eliza-type system

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Turing Test Criticism

• Provides weak equivalence where two systems are
  computing the same function (or generating the
  same external behavior), but that they are using
  different procedures to do so
• No restrictions on the judge
• Only tests for complete success
• Not a sufficient condition for intelligence

Alan Turing Turing Test
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Turing Test Criticism
From Turing Test Considered Harmful

• Doesnt take into account vision and robotics,
  places all emphasis on natural language
• Hard to completely define the experimental
  conditions and has no stable end point
• Test for complete success only and can be fooled
  by an artificial con artists
• There is a species detection aspect that is silly
  like to try to paste feathers and a beak on
  airplanes
• Continues to give AI a bad name

Turing test Hayes and Ford
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Turing Test Criticism
From Turing Test Considered Harmful

• An adequate test should focus on more general
  principles of cognition
• All of computer science is AI
• Perhaps Turing deliberately picked a test of
  sexual identity because of his own problems with
  English society in the Fifties

Turing Test Hayes and Ford (cot)