Agent’s structure can be viewed as −
● Agent = Architecture + Agent Program
● Architecture = the machinery that an agent executes on.
● Agent Program = an implementation of an agent function.
Simple Reflex Agents
● They choose actions only based on the current percept.
● They are rational only if a correct decision is made only on the basis of current precept.
● Their environment is completely observable.
Condition-Action Rule − It is a rule that maps a state (condition) to an action.
Model Based Reflex Agents
They use a model of the world to choose their actions. They maintain an internal state.
Model − The knowledge about how the things happen in the world.
Internal State − It is a representation of unobserved aspects of current state depending on percept history.
Updating the state requires the information about −
● How the world evolves.
● How the agent’s actions affect the world.
Goal Based Agents
They choose their actions in order to achieve goals. Goal-based approach is more flexible than reflex agent since the knowledge supporting a decision is explicitly modeled, thereby allowing for modifications.
Goal − It is the description of desirable situations.
Utility Based Agents
They choose actions based on a preference (utility) for each state. Goals are inadequate when −
● There are conflicting goals, out of which only few can be achieved.
● Goals have some uncertainty of being achieved and you need to weigh likelihood of success against the importance of a goal.
