A detailed analysis of the nature of science as an information system is presented in this book translated from the Russian version by the Foreign Technology Division of the Wright-Patterson Air Force Base. An analysis is provided of the increase in numbers of publications, journals, and scientists. The effect of the information crisis on the development of informal networks of scientists who exchange pre-publication copies of research reports is outlined, and the effect of the growth of these "invisible collectives," which provide essentially private knowledge, on the progress of Russian science is discussed: in the past, Soviet scientists have contributed to, and depended upon, the public knowledge in the journals. The language of bibliographic citations, which can be used to establish conceptual relationships between publications, is discussed as an alternative to indexing via structured vocabularies. Difficulties with the evaluation of effectiveness of the invisible collectives in the absence of public bibliographic citation are outlined. The contribution of different countries to world science information flow is estimated. (AL)