ACT - A simple theory of complex cognition

In the Adaptive Character of Thought (ACT-R) theory, complex cognition arises from an interaction of procedural and declarative knowledge. Procedural knowledge is represented in units called production rules, and declarative knowledge is represented in units called chunks. The individual units are created by simple encodings of objects in the environment (chunks) or simple encodings of transformations in the environment (production rules). A great many such knowledge units underlie human cognition. From this large database, the appropriate units are selected for a particular context by activation processes that are tuned to the statistical structure of the environment. According to the ACT-R theory, the power of human cognition depends on the amount of knowledge encoded and the effective Employment of the encoded knowledge.