Rational agents

An agent should strive to "do the right thing", based on what it can perceive and the actions it can perform. The right action is the one that will cause the agent to be most successful

Performance measure: An objective criterion for success of an agent's behavior

E.g., performance measure of a vacuum-cleaner agent could be amount of dirt cleaned up with penalty for amount of time taken, amount of electricity consumed, amount of noise generated, etc.

Better: One point for a clean square at each time unit

Rational Agent: For each possible percept sequence, a rational agent should select an action that is expected to maximize its performance measure, given the evidence provided by the percept sequence and whatever built-in knowledge the agent has.

Rationality is distinct from omniscience (all-knowing with infinite knowledge)
Rationality <> Perfection



‘Looking’ actions - information gathering, exploration


Learning
Not completely known environment
Improve, not all information from the designer

An agent is autonomous if its behavior is determined by its own experience (with ability to learn and adapt)

Acting rationally: rational agent

Rational behavior: doing the right thing

The right thing: that which is expected to maximize goal achievement, given the available information

Doesn't necessarily involve thinking – e.g., blinking reflex – but thinking should be in the service of rational action


An agent is an entity that perceives and acts

Intelligent agents – more than mere programs – attributes such as operating autonomously, perceiving their environment, adapting to change

Uncertainty may be involved

For any given class of environments and tasks, we seek the agent (or class of agents) with the best performance

Computational limitations make perfect rationality unachievable



Logic reasoning is needed but not enough
Correct inference is just one of several possible mechanisms for achieving rationality
All the skills from the Turing test are needed

Thinking rationally: "laws of thought"

Aristotle: what are correct arguments - Yield correct conclusions when given correct premises
Several Greek schools developed various forms of logic: notation and rules of derivation
Direct line through mathematics and philosophy to modern AI: logicist tradition

1965 – programs that could, in principle, solve any solvable problem described in logic notation


Problems:
Not easy to take informal knowledge and state it in formal terms (particularly uncertain knowledge)
Solvable in principle <> practically solvable
Not all intelligent behavior is mediated by logical deliberation
What is the purpose of thinking? What thoughts should I have?