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:
“The decision to have a child is both a private and a public decision, for children are our collective future.”
—Sylvia Ann Hewitt (20th century)
“... cooking is just like religion. Rules don’t no more make a cook than sermons make a saint.”
—Anonymous, U.S. cook. As quoted in I Dream a World, by Leah Chase, who was quoted in turn by Brian Lanker (1989)