to practical Introduction. Besides, depending on the significance of problems being solved the S&T programmes are subdivided into Ali-Union,,republic:an,sectoral and regional according to management levels. - f'lan duration A particular role In the Implementation of single S&T pol Icy and S&T development planning is played by the plans of various duration: long-term plans (10-20 years), medium-term (5 ye~rs) and short-term (annual) plans. The system of S&T development plans of different duration makes It possible, on the one hand, to coordinate Integrally long-term objectives of socio-economic development of the country and those of S&T policy. and, on the vther hand. to ensure real lzation of these objectives through the structure of the state plans taking Into account of time required for the solu~lon of S&T problems. The long-term planning Is based on the c~mplex programme of S&T progress for a period of 20 years. Estimates of this progrmme for 15-20 year duration have a forecasting character whereas 10-year estimates serve as the Initial basis for the elaboration of the principal Guidelines of economic and social development of the country. Proceeding from the long-term objectives of a single S&T pol Icy which are specified In the Complex Programme the Principcl Guidelines for a given planning period define principal assignments of S&T progress, technlco-economlc level of develop­ ment of the national economy branches, I 1st of the most Important scientific and technological problems and directions of R&D activities. These assignments for the USSR ministries and departments and those of Union republ lcs are defined In the form of target figures for basic Indicators for the perspective period broken down by years of the next five-year period and brought to the 'l/2 notice of amalagamatlons, enterprises and organizations which elaborate on their basic five-year and annual S&T development plans. Plan Indicators 
**Analysis**
The text appears to be discussing the planning and implementation of science and technology (S&T) policies and programs, with a focus on long-term planning and goal-setting. It mentions the development of national economy branches, scientific and technological problems, and research and development (R&D) activities. The text also references the coordination of S&T policies with socio-economic development objectives, which suggests a connection to economic development. However, the text does not explicitly mention economic development or any specific sectors, making it difficult to categorize solely under one category.

**Category**
Science and technology, Economic development