Patent ID: 7472121
Filing Date: 2008-12-30
Classification: G06F,Y10S

Abstract:
1. A method of comparing a plurality of documents, said method comprising: determining a plurality of similarity measures for said plurality of documents; and determining an overall similarity measure for said plurality of documents, based on said plurality of similarity measures, wherein said plurality of similarity measures are chosen from the group of similarity measures comprising: wherein said plurality of similarity measures include a semantic similarity measure and a reference similarity measure, and further wherein two documents P and wherein if terms k and l belong to ontology classes Ck and Cl, respectively, w tf tf idf(Ck) represents the inverse document frequency of class Ck in document corpus of document i and is calculated as: log idf(Cl) represents the inverse document frequency of class Cl in document corpus of document j and is calculated as: log sim(Ck, Cl) is calculated as: where p Ck is the probability of encountering the class Ck or a child of the term in a given taxonomy, p Cl is the probability of encountering the class Cl or a child of the term in a given taxonomy and p min is the minimum probability among common ancestors of classes Ck and Cl, and WT