accordance with the method of research employed. The first group Includes all the methods with simulation In the base. The research, carried out by this means, employs ana I ogy for bu I I dIng a mode I. These methods are used· for Investigating compl lcated phenomena, consisting of Interrelated events. The stated methods are employed for Investigating operations by means of digital and analogue models. More precise digital models are used In case of more complete knowledge of the dependences and Interrelationships between Individual components of the phenomenon. These' methods lnclude·also those that employ system analysis. The development of economic-mathematical models has made It possible to create a series of models of the national economy, whose appl lcatlon In the elaboration of the Complex Program of scientific-technical progress enabled to Judge the final effectiveness of different scientific-technical measures by large-aggregate blocks. Future models, considering several thousand parameters, are developed at the Institutes of the USSR Academy of Sciences. This type of research Is carried out also In the commissions of the Committee of scientific-technical prognostication of the AI!­ Union Council of Scientific-Technical Societies. The second group Includes methods of prognostication that use statistical data In one or the other way, c Jl led a group of methods of statistical prognostication. The basis of these methods Is extrapolation of tendencies and regularities of deve­ lopment In the future. The following methods are characteristic representative of this group: -direct extrapolatlo~; -extrapolation by a logistic curve; -the methods of analysing patents (~ubllcatlons). The first and second methods practically extend the character and the tendencies of current development Into the future. In the first-case It occurs along a straight line, and In the second -by the logistic curve. The first method Is good owing to Its slmpl lefty for medium-term prognoses. Tne second 
**Analysis**
The text discusses various methods of research and analysis used in the field of economics, specifically in the context of scientific-technical progress and national economy. It mentions the development of economic-mathematical models, extrapolation of tendencies and regularities, and analysis of patents. The text does not mention any specific natural resources, environment, agriculture, forestry, fishing, transport, communication, international trade, health, education, employment, humanitarian aid, or culture-related topics. Therefore, it is likely that the text is related to the field of economics and science.

**Category**
Science and technology, Economic development