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Introduction to Artificial
Intelligence
Artificial Intelligence
Section 4
Mr. Sciame
Definitions
• Artificial Intelligence is the ability of a
machines to do things that people would
say require intelligence.
• AI research is an attempt to discover
and describe aspects of human
intelligence that can be simulated by
machines.
What Computers Can Do
• Play games
– And learn from them
• Learn to recognize visual or auditory
patterns
• Find proofs for mathematical theorems
• Solve certain, well formulated kinds of
problems
• Process information expressed in human
languages
Basic Goal of AI Research
• To construct a machine that exhibits the
behavior associated with human intelligence
(comparable to the intelligence of a human
being).
– The machine does not have to use the same
underlying mechanisms used in human cognition.
– The machine does not have to go through stages
of development and learning such as those
through which people progress.
Alan Turing
• Alan Turing proposed an
operational test of
intelligence as a
replacement for the
philosophical question,
"Can machines think?"
Variations of this test
have been used to assess
performance levels of
many AI programs.
• Turing's contributions to
mathematics, computer
science and early AI
extend well beyond his
seminal paper proposing
the test.
The Turing Test
• In the Turing test, a judge has conversations (via
teletype) with two systems, one human, the
other a machine.
• The conversations can be about anything, and
proceed for a set period of time (e.g., an hour).
• If, at the end of this time, the judge cannot
distinguish the machine from the human on the
basis of the conversation, then Turing argued that
we would have to say that the machine was
intelligent.
Diagram of Turing Test
Comments on Turing Test
1. The interrogator does not observe the physical nature
of the subjects; only the intellectual behavior is
observed.
1. Can it fry an egg?
2. Either a machine will pass the Turing test, or a valid
proof that no machine can pass it will be found.
1. Therefore, no such machine can be constructed.
3. What if more than 1 machine passes the Turing Test?
1. A general description then must be made.
4. If created, there would be a machine that surpasses
human intelligence
Straight from Miriam-Webster
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•
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in·tel·li·gence
Pronunciation: \in-ˈte-lə-jən(t)s\
Function: noun
Etymology: Middle English, from Middle French, from Latin
intelligentia, from intelligent-, intelligens intelligent Date:
14th century
• (1): the ability to learn or understand or to deal with new
or trying situations : reason ; also : the skilled use of reason
(2): the ability to apply knowledge to manipulate one's
environment or to think abstractly as measured by
objective criteria (as tests)
• B Christian Science : the basic eternal quality of divine Mind
c: mental acuteness : shrewdness
Continued Miriam-Webster
•
•
•
•
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2 a: an intelligent entity ; especially : angel
b: intelligent minds or mind <cosmic intelligence>
3: the act of understanding : comprehension
4 a: information , news
b: information concerning an enemy or possible
enemy or an area ; also : an agency engaged in
obtaining such information
• 5: the ability to perform computer functions
Natural Intelligence
• To summarize the definitions on the last
two slides, intelligence is the ability to
“act rightly in a given situation.”
• An AI computer can make mistakes, but
can also change its behavior and stop
making mistakes.
Human Intelligence
• Limited, but can learn and improve
performance in certain tasks.
• While there are “Intelligence Tests”, little is
known concerning the limitations to
intelligence.
– These tests predict little concerning the
development of a person’s intelligence;
particularly what problems a person can solve.
Evidences of Human
Intelligence
• Comes from 4 sources:
– History
– Introspection
– The Social Sciences
– The Biological Sciences
History
• There is too much to discuss here in
this class
– People who claim the ancients were smarter
(navigation)
– The letter writing during the Civil War
– People who look at all we have/done and say
we’re the smartest generation.
Introspection
• “I think, therefore I exist.” Rene
Descartes
• He felt:
– Animals not much different from machines.
– People are different from animals since
they communicate effectively
– “The ability to use languages is the most
significant indication that something has
human intelligence.”
Introspection and
Nonintellectual Learning
• Some notions of nonintellectual learning:
1. Subconscious Learning – Knowledge
obtained without conscious reasoning.
2. Emotional Learning – Knowledge perceived
as an emotion.
3. Inspired Learning – Given instantaneously
(by some deity).
4. Paradoxical Learning – Perceiving
knowledge that is self contradictory.
Introspective Introspection
• If some intelligence cannot be explained
logically or scientifically:
– There is some knowledge computers cannot possess, and
some ways of gaining knowledge that computers can’t use.
– Is there spiritual learning? If so, should our definition of AI
change to learning some forms of intelligence (and not all)
• The irony: Introspection is probably the
source most commonly used in artificial
intelligence research for information about
specific problem-solving abilities of human
intelligence.
Social Sciences
• What we know:
1. Human intelligence is species-wide.
2. Intelligence of an individual develops with
time and is strongly affected by the
nature of its environment.
3. Intelligence is strongly influenced by
heredity.
4. Intelligence varies with respect to
different problem domains (aptitudes)
Piaget’s Findings
• A child’s intelligence develops in stages
– We don’t know precisely why…
– These stages do exist.
– Each child must accumulate sufficient experience
within a stage before progressing to the next.
• Piaget distinguished 4 stages:
1.
2.
3.
4.
Sensory-motor
Preoperational
Concrete Operational
Formal Operational
Sensory-Motor Stage
• From birth to age 2
• The child goes from using only instincts
to an elementary ability to reason and
use signals.
• Examples:
– Depth Perception
– Cause and effect (It rattles when you
shake it)
– Vocal and body gestures
Preoperational Stage
• From age 2 to 7
• The child learns:
– Basic Vocabulary
– Expresses ideas in sentences (not single
words)
– Reading and writing begin towards the end
of this stage.
Concrete-Operational Stage
• From age seven to eleven
• Can start to judge (Which glass has
more water).
Formal Operations Stage
• From age 11 upward
• Can operate logically
• Can plan experiments to increase
knowledge
• Reasons abstractly
Biological Science
• Some discussion must
be given to the human
nervous system:
– The brain
– The neuron (pictured to
the left)
The Human Brain
Typical Brain Sitting Next to You