György Rózsa: Information: from claims to needs (Joint edition published by the Library of the Hungarian Academy of Sciences and the Kultura Hungarian Foreign Trading Company. Budapest, 1988)

I. The socio-professional aspects of the development of the scientific information with special regard to social sciences

68 These are average figures for the social sciences as a whole, but there are no large variations in this order between the different branches of the social sciences: 40-55 % for periodicals, 17-38 % for books, 9-23 % for reports and grey literature. The order of importance itself was the same in all the branches. Another result of the survey shows the obsolescence of the value of information as a function of time (the half-time of information obsolescence), which means that a given piece of information loses 50 7c of its value. Investigations of this kind are common in the natural and the technical sciences, but have been less frequent in the social sciences. (See the investigations by Maurice Line or the survey at University of Bath.) The Czechoslovak investigations have also proved the assumption that the obsolescence of information in the social sciences is slower than in the natural and in the technical sciences, but much faster than it is generally believed. It was found that the half-time of information obsolescence in the social sciences of the Czechoslovak Academy of Sciences was 3.92 years. Only 25 % of the information needed in the social sciences was "over ten years old ". The particular needs of the different branches of the social sciences no doubt influence the half-time of information obsolescence in a given field. The branches influenced by the scientific and technical revolution and the accelerating social mobility, especially economics and sociology, rely to a larger extent on "fresh" information than, for example, history. The large variations in the different half-periods of information obsolescence between economics (2.28 years) and history (6.49 years), between philosophy and sociology (3.7 years) and literature (8.48 years) show the considerable variations that exist between the different lengths of time each source of information can be used. This calls for the specific treatment and handling of the different sources of information as far as collection, storing and selection are concerned. The concept of "social science information" is a kind of necessary simplification rather than the exact description of the subject which is far more complex both in its contents and function. When evaluating the above results of half-times, the limited sampling possibilities should also be borne in mind. The different branches of the social sciences may be divided into three basic groups and one mixed group, according to the different written sources their research activities are based on. In this way we distinguish: a) special literature-oriented branches b) factographic-oriented branches c) data-oriented branches and a group comprising the three types of orientation, mixture of orientation а—с branches. Written and printed sources are of basic importance in social science research. In certain branches daily newspapers and in others literature may be just as important as scientific or special literature. The study of printed texts is not always the basis or starting point of research. There are other, primary sources of research that have become written sources only after they had been described in writing. Such sources are.