Abstract: There is disclosed a scheme for accessing data management directory which is capable of achieving easy and flexible data access which are managed in substantial directories from respective applications by constructing substantial directories which sort and manage the location of data accumulated on the network and access information independently from the applications, and then sharing and integrating a group of these substantial directories to show a directory structure which is easy for the applications to utilize.

Abstract: An information retrieval scheme using classification trees with respect to a plurality of information sources connected to a network is disclosed, where each classification tree having a hierarchical structure defined in terms of entries. In the information retrieval apparatus, classification tree class information for each classification tree class defined among entries constituting each classification tree is managed, where each classification tree class information indicating retrieval condition parameters for each classification tree class.