Conflict resolution strategy

Conflict resolution strategies are used in production systems to help in choosing which production rule to fire. The need for such a strategy arises when the conditions of two or more rules are satisfied by the currently known facts.

Categories

Conflict resolution strategies fall into four main categories:

  1. Specificity - If all of the conditions of two or more rules are satisfied, choose the rule with the most specific conditions. (e.g. "it is hot and smokey" rather than "it is hot"). Also referred to as "degree of specialization".
  2. Recency - Facts are usually tagged to show how recently they were added. When two or more rules could be chosen, favor the one that matches the most recently added facts. This helps to utilize the most recently relevant facts.
  3. Refractorizenes - If a rule's conditions are satisfied, but previously the same rule has been satisfied by the same facts, ignore the rule. This helps to avoid the system from entering infinite loops.
  4. Order - Pick the first applicable rule in order of presentation. This is the type of strategy that Prolog uses and is one of the most common ones.

See also