agent types (slides2) Flashcards
four types of agents
simple reflex, model based reflex, goal based, utility based
simple reflex agent code
function SIMPLE-REFLEX-AGENT(percept) returns an action
persistent: rules, a set of condition-action pairs
state <– rule.ACTION return action
action only depends on percept
model based reflex agent
- to cope with partial observability the agent keeps track of the part of the world it cannot see
- Internal state of environment depends on sequence of percepts
- model: how the world evolves independently of the agent, how the actions of agent affect the world
- current state usually not exact
- described succinctly
model-based reflex agents code
function MODEL-BASED-REFLEX-AGENT(percept)
returns an action
persistent:
state, the agent’s current conception of the world state
model, description of how next state depends on current state and action
rules, set of condition-action pairs
action, the most recent action, initially none
state <– rule.ACTION
return action
search and planning
important for model-based and Goal-based agents,
seek action sequences that achieve goals.
flexible, since they dont require rewriting condition rules when the goals change
utility-based agents
not all ways to achieve goals are equally good
Goals enable distinguishing between satisfied an unsatisfied
UTILITY FUNCTION represents performance measure of level of satisfaction
Utilities are when there are conflicting goals, or many possible goals
Rationality maximizes expected utility
Learning Agents
Better than programming intelligence directly
ability to cope directly with unknown environments
Learning Agent Components
learning element performance element critic possible utility problem generator
learning element
responsible for making improvements
-can change any component of the agent
performance element
the actual agent
critic
assesses how well the agent is performing w.r.t. a fixed performance standard (e.g. checkmate)
problem generator
generates actions that yield an information gain(otherwise the ones that are best given the current knowledge would always be chosen)
-May suggest suboptimal actions which lead to find better actions in the long run
Utility function
Represents performance measure of level of satisfaction