Patent ID: 7409404

Claim:
A computer implemented method comprising generating from a plurality of training documents at least one set of features representing at least one category, the step of generating comprising employing a computer in obtaining or storing said at least one set of features, and the step of generating further comprising the steps of: forming a first list of items wherein each item in said first list represents a particular training document having an association with at least one element related to a particular category; developing a second list from said first list by deleting at least one candidate document which satisfies at least one deletion criterion; and extracting said at least one set of features from said second list using at least one feature selection criterion; grouping together items from said first list into at least one supercategory based upon at least one supercategory formation criterion; wherein the supercategory formation criterion includes: applying an initial set of training documents and selecting an initial set of features, using said initial set of features in defining a supercategory; forming a third list of items wherein each item in said third list represents the particular training document having said association with at least one element related to said particular category; determining a similarity of each training document in said third list to each feature of said set of initial features selected from said initial set of training documents; and assigning each item in said third list to a particular supercategory by selecting the set of initial features to which said item is most similar.