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:
“Once the decision has been reached, close your ears even to the best counter-argument: a sign of strong character. Thus an occasional will to stupidity.”
—Friedrich Nietzsche (1844–1900)
“But suppose, asks the student of the professor, we follow all your structural rules for writing, what about that “something else” that brings the book alive? What is the formula for that? The formula for that is not included in the curriculum.”
—Fannie Hurst (1889–1968)