Inteligencia Artificial

6.825 Techniques in Artificial Intelligence

What is Artificial Intelligence (AI)?

Lecture 1 • 1

If you're going to teach or take an AI course, it's useful to ask: "What's AI?"
It's a lot of different things to a lot of different people. Let's go through a few
things that AI is thought to be and situate them within the broader picture of
AI.

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6.825 Techniques in ArtificialIntelligence

What is Artificial Intelligence (AI)?
• Computational models of human behavior?
• Programs that behave (externally) like humans

Lecture 1 • 2

One thing it could be is "Making computational models of human behavior".
Since we believe that humans are intelligent, therefore models of intelligent
behavior must be AI. There's a great paper by Turing who really set up this
idea ofAI as making models of human behavior (link). In this way of thinking
of AI, how would you proceed as an AI scientist? One way, which would be
a kind of cognitive science, is to do experiments on humans, see how they
behave in certain situations and see if you could make computers behave in
that same way. Imagine that you wanted to make a program that played
poker. Instead of making the bestpossible poker-playing program, you
would make one that played poker like people do.

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6.825 Techniques in Artificial Intelligence

What is Artificial Intelligence (AI)?
• Computational models of human behavior?
• Programs that behave (externally) like humans

• Computational models of human “thought”
processes?
• Programs that operate (internally) the way humans do

Lecture 1 •3

Another way is to make computational models of human thought processes.
This is a stronger and more constrained view of what the enterprise is. It is
not enough to make a program that seems to behave the way humans do;
you want to make a program that does it the way humans do it. A lot of
people have worked on this in cognitive science and in an area called
cognitive neuroscience. Theresearch strategy is to affiliate with someone
who does experiments that reveal something about what goes on inside
people's heads and then build computational models that mirror those kind
of processes.
A crucial question is to decide at what level to mirror what goes on inside
people's heads. Someone might try to model it a very high-level, for
example, dividing processing into high-levelvision, memory, and cognition
modules; they try to get the modularity to be accurate but they don't worry
too much about the details of how the modules are implemented. Other
people might pick the neuron as a kind of computational unit that feels like
it's justified in terms of neurophysiology, and then take that abstract neuron
and make computational mechanisms out of it. It seems justifiedbecause
we know that brains are made out of neurons. But then, if you talk to people
that study neurons, you find that they argue a lot about what neurons can
and can't do computationally and whether they are a good abstraction so
maybe you might want to make your models at a lower level. So, it’s hard to
know how to match up what we know about brains with computational
models.

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6.825Techniques in Artificial Intelligence

What is Artificial Intelligence (AI)?
• Computational models of human behavior?
• Programs that behave (externally) like humans

• Computational models of human “thought”
processes?
• Programs that operate (internally) the way humans do

• Computational systems that behave intelligently?
• What does it mean to behave intelligently?

Lecture 1 •4

Another thing that we could do is build computational systems that behave
intelligently. What do we mean here? When we talked about human
behavior, we said that it was intelligent because humans are intelligent (sort
of by definition), so what humans do has to be intelligent. In this view, we
say that there might be other ways of being intelligent besides the way
humans do it. And so...