Meta data-a key to data acquisition and information retrieval

Meta data have a long tradition in several areas. Meta data help to structure data or documents and to classify the contents. It is important to recognize the power of existing meta data (thesauri, classifications, etc.) and to use such meta data and to expand such meta data for advanced data acquisition and information retrieval. To expand meta data modern learning systems should be used and an open communication model that integrates different aspects of data and meta data. Results of an information retrieval project are described and a new multi-level model of meta data is introduced