Conflict resolution


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Conflict resolution

In deciding what rule to pick from the conflict set, most production systems use one or more of these principles:

  1. Specificity. If two rules could be chosen, pick the one whose conditions are most specific. E.g. ``it has wings and swims'' over ``it has wings''.

  2. Refractoriness. If a rule could be chosen, but it has matched exactly the same data before and been chosen, then ignore it. This helps to stop the system getting into infinite loops.

  3. Recency. In most production systems, facts in short term memory are tagged to indicate how recently they were added. If two rules could be chosen, prefer the one that matches the most recent facts. I used refractoriness in my example, but recency would have given the same results.


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Jocelyn Ireson-Paine
Wed Feb 14 23:40:08 GMT 1996