Artificial Intelligence - Old Questions

2.  What are rational agents? How episodic task environment differs from sequential task environment? Support your answer with suitable examples.

A rational agent is an agent which has clear preferences and models uncertainity via expected value. It always performs right action, right action  means the action that causes the agent to be most successful in the given percept sequence.

Rational agent is capable of taking best possible action in any situation.

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.

Episodic task environment vs Sequential task environment

In Episodic environment, the agent's experience is divided into atomic 'episodes' (each episode consists of the agent perceiving then performing a single action i.e. agent's single pair of perception & action) and every episode is independent of each other. The subsequent episodes do not depend on actions occured in previous episodes. For e.g. an agent sorting defective part in an assembly line, pick and place robot agent.

In Sequential environment, current actions may affect all future decisions. In sequential environment, an agent requires memory of past action to determine the next best action. For e.g. a taxi driving agent or Chess playing.