Characteristic Rule Discovery in Aurum-3

One strategy for increasing the efficiency of rule discovery in data mining is to target a restricted class of rules, such as exact or almost exact rules, rules with a limited number of conditions, or rules in which each condition, on its own, eliminates a competing outcome class. An algorithm is presented for the discovery of rules in which each condition is a distinctive feature of the outcome class on its right-hand side in the subset of the data set defined by the conditions, if any, which precede it. Such a rule is said to be characteristic for the outcome class. A feature is defined as distinctive for an outcome class if it maximises a well-known measure of rule interest or is unique to the outcome class in the data set. In the special case of data mining which arises when each outcome class is represented by a single instance in the data set, a feature of an object is shown to be distinctive if and only if no other feature is shared by fewer objects in the data set.