A set of decision rules is the verbal equivalent of a graphical decision tree, which specifies class membership based on a hierarchical sequence of (contingent) decisions. Each rule in a set of decision rules therefore generally takes the form of a Horn clause wherein class membership is implied by a conjunction of contingent observations.
- IF AND AND ... AND THEN CLASS =
where is in general contingent on the choice of . Decision rules can be transcribed from the corresponding decision tree, or can be induced directly from observations.
Decision rules are commonly used in the medical field. For example, the Ottawa Ankle Rules guide obtaining radiographs for traumatic ankle pain.
C4.5 is a well-known tool for discovering decision rules. There has been work done on discovering temporal decision rules, where the condition attributes are observed before the decision attribute.
Famous quotes containing the words decision and/or rules:
“How could a man be satisfied with a decision between such alternatives and under such circumstances? No more than he can be satisfied with his hat, which he’s chosen from among such shapes as the resources of the age offer him, wearing it at best with a resignation which is chiefly supported by comparison.”
—George Eliot [Mary Ann (or Marian)
“Isn’t the greatest rule of all the rules simply to please?”
—Molière [Jean Baptiste Poquelin] (1622–1673)