Rules and Expert Systems

• One of the early big successes of AI was expert systems.
• While case based reasoning is a form of ES, ESs are almost synonymous with rule based systems.
• Rules are just a collection of if then clauses.
• You have a set of facts, and a set of rules.
• The facts support rules.
• There is a recognise act cycle. The rules that are supported by the facts are selected. Typically, one of them is applied. This may or may not add a fact. The cycle begins again, and a new rule is selected.
• This repeats until there are no rules to fire.
• This works pretty well because a lot of expert knowledge can be encoded as rules.
• Also, people are pretty good at stating their knowledge in the form of rules.
• Now try the Clips lab.