Model-based reasoning

In artificial intelligence, model-based reasoning refers to an inference method used in expert systems based on a model of the physical world.

Knowledge representation
In a model-based reasoning system knowledge is repesented using causal rules. For example, in a medical diagnosis system the knowledge base may contain the following rule:
 * $$\forall$$ patients : Stroke(patient) $$\rightarrow$$ Confused(patient) $$\land$$ Unequal(Pupils(patient))

In contrast in a diagnostic reasoning system knowledge would be represented through diagnostic rules such as:
 * $$\forall$$ patients : Confused(patient) $$\rightarrow$$ Stroke(patient)
 * $$\forall$$ patients : Unequal(Pupils(patient)) $$\rightarrow$$ Stroke(patient)