Knowledge level
Encyclopedia
In artificial intelligence, knowledge-based agents draw on a pool of logical sentences to infer conclusions about the world
. At the knowledge level, we only need to specify what the agent knows and what its goals are; a logical abstraction separate from details of implementation.
This notion of knowledge level was first introduced by Allen Newell
in the 1980s, to have a way to rationalize an agent's behavior. The agent takes actions based on knowledge it possesses, in an attempt to reach specific goals. It chooses actions according to the principle of rationality
.
Beneath the knowledge level resides the symbol level
. Whereas the knowledge level is world oriented, namely that it concerns the environment in which the agent operates, the symbol level is system oriented, in that it includes the mechanisms the agent has available to operate. The knowledge level rationalizes the agent's behavior, while the symbol level mechanizes the agent's behavior.
For example, in a computer program, the knowledge level consists of the information contained in its data structures that it uses to perform certain actions. The symbol level consists of the program's algorithms, the data structures themselves, and so on.
World
World is a common name for the whole of human civilization, specifically human experience, history, or the human condition in general, worldwide, i.e. anywhere on Earth....
. At the knowledge level, we only need to specify what the agent knows and what its goals are; a logical abstraction separate from details of implementation.
This notion of knowledge level was first introduced by Allen Newell
Allen Newell
Allen Newell was a researcher in computer science and cognitive psychology at the RAND corporation and at Carnegie Mellon University’s School of Computer Science, Tepper School of Business, and Department of Psychology...
in the 1980s, to have a way to rationalize an agent's behavior. The agent takes actions based on knowledge it possesses, in an attempt to reach specific goals. It chooses actions according to the principle of rationality
Principle of rationality
In the context of knowledge-based systems, Newell proposed the following principle of rationality:This principle is employed by agents at the knowledge level to move closer to a desired goal.-See also:*Artificial intelligence...
.
Beneath the knowledge level resides the symbol level
Symbol level
In knowledge-based systems, agents choose actions based on the principle of rationality to move closer to a desired goal. The agent is able to make decisions based on knowledge it has about the world . But for the agent to actually change its state, it must use whatever means it has available...
. Whereas the knowledge level is world oriented, namely that it concerns the environment in which the agent operates, the symbol level is system oriented, in that it includes the mechanisms the agent has available to operate. The knowledge level rationalizes the agent's behavior, while the symbol level mechanizes the agent's behavior.
For example, in a computer program, the knowledge level consists of the information contained in its data structures that it uses to perform certain actions. The symbol level consists of the program's algorithms, the data structures themselves, and so on.