Patent ID: 7979473

Claim:
A method of, when a pair of an attribute and an attribute value in a database are an item, a combination of items are an itemset and an association rule is composed of an antecedent and a consequent, each of which is an itemset, extracting an association rule holding true among two or more items in which the attribute value is not missing, from a database consisting of records in which zero or more attribute values are missing, comprising: a first step of partitioning the database into record units in which the same attribute is a missing value; a second step of counting a support count, which is the number of records in which an itemset including a specific attribute is included, in the record units; a third step of, based on the support count, for all itemsets of the entire database calculating the number of records which include the itemset; a fourth step of generating an association rule in which an antecedent is a sub-itemset of one of the itemsets and a consequent is a remaining itemset of said one of the itemsets excluding said sub-itemset; and a fifth step of excluding said specific attribute from analysis objects.