A COMPUTER‐AIDED INFORMATION SERVICE FOR NUCLEAR SCIENCE AND TECHNOLOGY

The computerized information centre of the European Atomic Energy Community has become operational. A survey of its principal characteristics is given, and the main problems that arose in the development phase of the system are discussed. The Euratom Thesaurus includes graphic representation of relationships between indexing terms. A dual vocabulary allows specific indexing for high relevance and generic indexing for high recall. Retrieval strategy involves utilization of Boolean operators and frequency‐of‐occurrence tables. Recall ratio can be determined graphically by a continuous approach method. Indexing consistency tests show that it pays to use subject specialists. Users' needs are discussed in terms of subject coverage, specificity, rapidity, and presentation. The user service comprises retrospective searches on request as well as a customer profile service on subscription. There are three types of relevance, and various ways of bringing system relevance to coincide with user relevance. The Centre's budgetary requirements are low, due to circumspect use of its computer, an IBM 360, model 40. Its aims are centralization of documentation in the nuclear field and international co‐operation.