Machines can be Scruffy Scruffy machines can be designed Cognitive models of Human Problem Solving Cognitive Architectures The CMS is a scruffy Cognitive Architecture

Machines do not have to be neat in their construction: they can be scruffy in their design. There are cognitive models of human problem solving, and such models do not need to be totally logical in their high level organisation. Clearly at some low level the machine model is logical - eg at the machine instruction set level - but the same could be said of the neural level of human thinking. Cognitive architectures can be based on our understanding of human cognition, and use models of learning, memory, perception. The Contextual Memory System is explicitly designed to be a psychologically plausible model of learning and memory, and it is exceptionally scruffy in its organisation. But it works.