C SC 421: Artificial Intelligence
Transcript C SC 421: Artificial Intelligence
C SC 421: Artificial Intelligence
• …or Computational Intelligence
What is AI?
• American Association for Artificial
– "the scientific understanding of the
mechanisms underlying thought and
intelligent behavior and their embodiment
What is AI? Differently said…
. . . Exactly what the computer provides is the
ability not to be rigid and unthinking but,
rather, to behave conditionally. That is what
it means to apply knowledge to action: It
means to let the action taken reflect
knowledge of the situation. . .
In late 1955, Newell and Simon developed
The Logic Theorist, considered by many to
be the first AI program.
The program, representing each problem as a
tree model, would attempt to solve it by
selecting the branch that would most likely
result in the correct conclusion.
In 1956 John McCarthy regarded as the
father of AI, organized a conference to draw
the talent and expertise of others interested
in machine intelligence for a month of
He invited them to Vermont for "The
Dartmouth summer research project on
From that point on, because of McCarthy, the
field would be known as Artificial
In the seven years after the conference, AI began to
pick up momentum.
Centers for AI research began forming at Carnegie
Mellon and MIT.
New challenges were faced: further research was
placed upon creating systems that could efficiently
And second, making systems that could learn by
SHRLDU has just completed the command:
“Find a block which is taller than the one you are holding and put on the box”
Example of microworld.
• The first difficulty was the intractability of many
of the problems that AI was attempting to solve.
• Most of the early AI programs solved problems by
trying out different combinations of steps until a
solution was found.
• This strategy worked out initially because
microworlds contained very few objects.
• It was widely thought that “scaling up” was
simply a matter of faster hardware.
• Well, not quite… a lot of research was done to
• Another advancement in the 1970's was the advent
of the expert system. Expert systems predict the
probability of a solution under set conditions.
• The applications in the market place were
extensive, and over the course of ten years, expert
systems had been introduced:
– to forecast the stock market,
– aiding doctors with the ability to diagnose disease, and
– instruct miners to promising mineral locations.
• During the 1980's AI was moving at a faster
pace, and further into the corporate sector.
• General Motors, and Boeing relied heavily
on expert systems.
• To keep up with the demand for the
computer experts, companies such as
Teknowledge and Intellicorp specializing in
creating software to aid in producing expert
AI application in other fields of CS
– Query processing: the promise (not yet fully achieved) that
the user can give any query and the DB query processor will
re-express it into an optimal one.
– Data mining: An information extraction activity whose goal
is to discover hidden facts contained in databases.
• Using a combination of machine learning, statistical analysis,
modeling techniques and database technology, data mining finds
patterns and subtle relationships in data and infers rules that allow
the prediction of future results.
• Typical applications include market segmentation, customer profiling,
fraud detection, evaluation of retail promotions, and credit risk
• Web computing:
– Software robots which search for different things in the Web.
The course covers three major topics:
– Tree/Graph search
– Constraint Satisfaction
• Knowledge Representation & Inference
– Propositional & First Order Logic
– Rule-based systems
– Natural Language
• Machine Learning