Knowledge component: A piece of information that can be used to accomplish tasks, perhaps with other knowledge components. It is a generalization of everyday terms like concept, principle, fact, skill, and cognitive science terms like schema, production rule, facet. A knowledge component relates features to a response where both the features and response(s) can be either external, in the world, like cues in a stimulus and a motor response or internal, in the mind, like inferred features and a new goal.