Describes the principles and methodology of Warsaw Clearinghouse activity and its specialized bibliographic service for collecting, processing, and disseminating information on thesauri and related topics. An information retrieval system TEKLA, designed to improve clearinghouse service, is discussed. (Author/BK)

Brief discussion of state-of-the-art of modeling complex information systems distinguishes between macrolevel and microlevel modeling of such systems. Network layout and hierarchical system models, simulation, information acquisition and dissemination, databases and information storage, and operating systems are described and assessed. Thirty-four…