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 women of my mother’s generation had, in the main, only one decision to make about their lives: who they would marry. From that, so much else followed: where they would live, in what sort of conditions, whether they would be happy or sad or, so often, a bit of both. There were roles and there were rules.”
—Anna Quindlen (20th century)
“Can rules or tutors educate
The semigod whom we await?
He must be musical,
Tremulous, impressional,
Alive to gentle influence
Of landscape and of sky
And tender to the spirit-touch
Of man’s or maiden’s eye.”
—Ralph Waldo Emerson (1803–1882)