Not all knowledge is in the head of the person thinking. Cognition is typically social and takes place among the members of teams and groups. Problems are seen as about physical causality, not about logical consistency. Because of the limits of attention dynamics, not all variables are monitored by operators, Instead they make use of mental models which are homomorphic mappings of the physical system. Operators simplify systems by thinking of them as made up of partly independent subsystems which can be considered independently.
Operators make extensive use of mental look-up tables rather than reasoning.
Operators have many mental models of a single system which represent different levels of an abstraction hierarchy, different levels of part-whole decomposition, and different types of causality. Operators change the levels or types of cognition from moment to moment within a problem. This hierarchy has been suggested as a model of cognition, but has not been implemented. Artificial cognition should mimic the errors made by humans as well as providing successful reasoning. The form of errors reflect the skill, rule, knowledge typology.