The concept of a statistical knowledge base implies that elements of information are organised in such a way that they can easily be retrieved, selected, combined and analysed within the system. DUVA is such a system. It has been developed by the KOSIS association DUVA over the last 25 years. Meanwhile, DUVA involves about 60 municipalities, state statistical institutes and research institutions. It
supports data entry, retrieval, evaluation and presentation of results via the Internet and is controlled by a common metadata system.
DUVA enhances standardisation and guarantees further development according to the user needs. Standard data descriptions for common data sources facilitate data exchange and cooperative learning. Examples are periodical excerpts from the population register, the employment and unemployment registers as well as flow data on migration, births, deaths and construction statistics. DUVA is also applied in projects of cooperative data collection, like the Urban Audit, and it is the central instrument in a project for the development of comparable tools for local surveys, supported by the EU. The DUVA system will be introduced at the conference, including examples of practical application and actual measures for further improvements. As a case of practical use the „Planning Related Information System for Spatial Monitoring“ (PRISMA) of the City of Berlin will be presented applying DUVA software components. An upgrade of the English version will be available this year, mapping facilities are being developed and further steps web based components will follow.