Patent ID: 7072907

Claim:
An information providing system comprising: a plurality of information sources each having both an information providing function of providing an information item upon receipt of a request from a user's client for the same, and each having an index output function of outputting an individual index indexing information items that is capable of providing from its information providing function, where the index output function and the information providing function are separate functions; retrieval engines each having an index construction function of receiving at least one individual index outputted by the index output function of at least one information source and constructing a general index indexing information items capable of being provided by the least one information source, and having an information retrieval function of retrieving information for a user upon receipt of a user request to retrieve information by referring to the general index constructed by the index construction function; and a mediating apparatus intervening between said information sources and said retrieval engines and adapted to receive a plurality of individual indexes outputted from said plurality of information sources, the mediating apparatus deciding which received individual indexes to send to which retrieval engines based on comparing the received individual indexes with a predetermined index selection condition, and sending the selected individual indexes to corresponding decided retrieval engines for use in the index construction functions of said retrieval engines.