reflects or instantiates a unified theory of human behavior (at least in the minds of its developers) in which related submodels interact through common representations of intermediate information processing results, and in which consistent conceptual representations and similar tools are used throughout.

This section reviews 11 integrative architectures (presented in alphabetical order):

• Adaptive control of thought (ACT-R)

• COGnition as a NEtwork of Tasks (COGNET)

• Executive-process interactive control (EPIC)

• Human operator simulator (HOS)

• Micro Saint

• Man machine integrated design and analysis system (MIDAS)

• MIDAS redesign

• Neural networks

• Operator model architecture (OMAR)

• Situation awareness model for pilot-in-the-loop evaluation (SAMPLE)

• Soar

The following aspects of each architecture are addressed:

• Its purpose and use

• Its general underlying assumptions

• Its architecture and functionality

• Its operation

• Features of its current implementation

• Its support environment

• The extent to which it has been validated

• The panel's assessment of its applicability for military simulations

It should be noted that the discussion of these models is based on documentation available to the panel at the time of writing. Most of the architectures are still in development and are likely to change—perhaps in very fundamental ways. The discussion here is intended to serve as a starting point for understanding the structure, function, and potential usefulness of the architectures. The organizations responsible for their development should be contacted for more detailed and timely information.

ACT-R is a "hybrid" cognitive architecture that aspires to provide an integrated