A system and method for automated populating of an existing concept hierarchy of items with new items, using entropy as a measure of the correctness of a potential classification. User-defined concept hierarchies include, for example, document hierarchies such as directories for the Internet, library catalogues, patent databases and journals, and product hierarchies. These concept hierarchies can be huge and are usually maintained manually. An internet directory may have, for example, millions of Web sites, thousands of editors and hundreds of thousands of different categories. The method for populating a concept hierarchy includes calculating conditional `entropy` values representing the randomness of distribution of classification attributes for the hierarchical set of classes if a new item is added to specific classes of the hierarchy and then selecting whichever class has the minimum randomness of distribution when calculated as a condition of insertion of the new data item.