Soar is designed to be a model of the human cognitive architecture. As such, it contains hierarchical levels that correspond to the hierarchical levels in the human architecture as described by Allen Newell in the Unified Theories of Cognition. Newell assumes that the human architecture contains levels that are strong enough to be identified and described individually. In particular he feels that the Biological Band the Cognitive Band and the Rational Band can each be described without an understanding of the levels below it. This concept of strong levels does not seem to hold well for the Social Band though because of the low bandwidth of communication between human agents.
Lower levels of the architecture are designed to operate at faster time scales. Increasingly higher levels or the architecture are composed of multiple actions at the lower levels and operate at increasingly slower time scales by factors of approximately 10. Productions provide symbol access and correspond to human neural circuits operating on the order of 10 ms. This represents the upper level of Newell's "Biological Band".
Context decisions such as operator selection corresponds to human deliberative acts which operate on the order of 100 ms. This represents the first level of the "Cognitive Band". The application and termination of operators corresponds to human operations operating on the order of 1 second. Impasse resolution corresponds to human unit tasks which operate on the order of 10 seconds and designate the upper boundary of the "Cognitive Band".
The emergent behavior of Soar, characterized by its added knowledge, corresponds to human tasks ranging from minutes to hours in length. Thus the knowledge that is added to soar composes the "Rational Band".
Go to a discussion of this property for multiple architectures.