text: could be selected and used to represent social values and goals, applying the interpretation of the users. 3 7. The comprehsnsiveness of he statistrcal series in SSDS could pro­ vide a good point of departure in formulating a country-specific social indicators structure. In using this global system, extreme care should be given in the process of selecting statistical series to be included in a country-specific system. Those included should be significant and rele­ vant in the context of current and near future development of the coun­ try concerned. Furthermore, SSDS would also serve as a useful reference 28 Although the proposed set of indicators i<l relatively small, it includes four indicators on non-human productive resources and five experimental indicators on political values, remind­ ing a reader of the world-wide resource cruis and the political situation in the Philippines in the early l 970s. 29 Towards a System of Social and Demographic Statistics, op. cit., pp. 3 -4. 45 to the statistician involved in a social indicators project, whose primary responsibilities are to provide the empirical contents of a conceptually formulated system and to enhance the efficiency and comprehensiveness of its data collection system. Providing statistical contents 38. In order to be practically useful, a conceived system of social indicators must be expressed in numbers, either cross-sectional and/or in time series. The sources of numerical data for social indicators are, of course, censuses, surveys, and reported statistics compiled by govern­ ment and private statistical agencies. Because of this interrelationship, social indicators are often identified as social or socio-demographic statis­ tics. 39. For developed countries, the provision of statistical contents to a social indicators system poses relatively little problem owing to the abun­ dance of available data, meeting most statistical requirements. Three conceivable problems relevant to providing the statistical contents of a system of social indicators often encountered in advanced countries are 
analysis: The text appears to be discussing the development of a system of social indicators, which is a broader concept that encompasses various aspects of society. The text mentions statistical series, censuses, surveys, and reported statistics, which suggests that the focus is on collecting and analyzing data to understand social phenomena. The text also mentions the Philippines and its development, which implies that the context is likely international development or global development.