Architectures: Definition and Discussion

Newell defines an architecture to be the fixed structure that realizes a symbol system which Newell maintains is necessary for realizing a sufficinetly complex knowledge-level system. Of course if we look at the human cognitive architecture, realized in neural circuit technology, we notice that very little of it is permanently immutable. What we should then consider are those structures that are fixed relative to a particular time scale.

Since the purpose of a UTC is to provide a functional description of a class of cognitive agents it should therefore describe the communality amongst the agents in this class. Because the architecture is the fixed processing structure of the agent, it describes how the variable content in the agent's memory will be processed. Since the architecture provides the basis for communality amongst agents with vastly different knowledge bases, formulation of a UTC amounts to a description of an architecture.

Newell makes a parallel to computer architectures by specifying the following functions that have been included in architectures classically:

• The fetch-execute cycle
  • Assemble the operator and operands
  • Apply the operator to operands - operators are chosen from a finite, specified list of primitive operations
  • Store results for later use
• Support access structures i.e. memory or symbol system
• Input and output