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.
Knowledge components are "correct" when all of the features are relevant to making the response and none of them are irrelevant. For example, in geometry the knowledge component "if angles look equal, then conclude they are equal" is incorrect because it includes an irrelevant feature "angles look equal" and is missing a relevant feature like "the angles are at the base of isosceles triangle".