the tasks of planning In Individual branches as wei I as In the development of the national economy proper. The document set the task of elaborating a complex prognosis of development of the national economy In the form of a "complex program of scientific-technical progress for 20 years (by five­ year periods)". Besides. the principle of complexity enables us to avoid lack of coordination that reduces the probability characteristics of prognoses. The principle of continuity has materiel I zed by Introducing cprrectlons Into the program two years before the beginning of the next five-year period. Thus, the complex program of scientific-technical prognosis became the major pre-plan document, specifying the trends of development of the national economy proper In a variant form. The practice of elaborating and utilizing the Complex program, developed tor the period up to the year 2000 and then up to 2005, has manifested In Its profound usefulness and the necessity of this document for elaborating the Basic directions of economic and social development of the USSR for 10 years, as well as substantiated selection of major scientific-technical problems that ought to be solved In the al 1-unlon scientific­ technical programs. Prognoses on Individual scientific-technical directions. as well as concrete prognoses of development of Individual branches of the national economy have been used as the basic materiels for the Complex Program. The methodological Instructions for the development of the Complex Program envisage consideration of different variants that. depending on the concrete factors of the external medium, permits the selection of the optimum variant of development. Economic-mathematical models have been used on a wide scale In the elaboration of the Complex Program, permitting to estimate by simulation of the effect of V8 Individual scientific-technical solutions on the final results of development of the national econo•y. The entire scope of work In the country on the elaboration 
**Analysis**
The text appears to be discussing the planning and development of the national economy, specifically the elaboration of a complex program for scientific-technical progress. It mentions the consideration of different variants, economic-mathematical models, and the estimation of the effect of individual scientific-technical solutions on the national economy. This suggests that the text is focused on the planning and development of the economy, rather than other areas such as natural resources, industry, or education.

**Category**
Economic development, Science and technology