Production_Systems

Cognative Architecture

• A cognative agent is a function f that maps a perceptual history P* to an action A.
• Percepts -> Actions
• The * stands for "history"

Assumptions of Cognative Architectures:

• Goal-oriented
• Rich, complex environments
• Significant knowledge
• Represented at a level of abstraction, symbols
• Respond flexibly to a changing environment
• Learn from their experiences

If architecture is fixed, then we only need to change the knowedge content of the agent to achieve different behaviors.

SOAR

Consists of a long term memory portion

• Procedural knowledge (how to pour water into a container)
• Semantic knowledge (concepts and models of the environment, model of how a plane flies in the air)
• Episodic knowledge (events, think what was for dinner yesterday)

and short term memory

• Working memory

Production Systems

Levels of Abstraction:

• High - Task / Knowledge Level

• Mid - Algorithm / Symbol Level

• Low - Hardware / Implementation Level

• Low level provides architecture for higher levels up ladder

• High level provides content for lower levels down ladder

Working Memory Cycle

• Working memory is the state of the system
• Long term memory can consist of "production rules"
• Based on long-term memory some rules get activated
• Rules which are activated consequences get established
• Consequences that are established mutate working memory

If SOAR reaches a state that it cannot determine an action for, it will envoke episodic knowledge to try and learn a new behavior

Action Selection

Mapping percepts in the world into actions

• Percepts from the world into a pitch selection

Chunking

• A learning technique that SOAR uses to overcome impasses
• Uses episodic memory to find an event in the past that is related to current percepts and leverages the previous event into a new rule

Misc

Reasoning first, then work backwards to learning