Production_Systems
Cognative Architecture
- A cognative agent is a function
f
that maps a perceptual historyP*
to an actionA
. - 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