The methodological question concerns constructing a cardinal social index, in order to assess performances of social agents, taking into account implicit political judgments. Based on the formal structure of a Choquet's expected utility, index construction demands quantification of levels of a meaningful ordinal indicator of overall performance. Contrasting common praxis of using equidistant interval scale, level increments are formally interpreted as variations of social utility. The social scaling is implicitly designed over an evaluative-framework, which is depicted using specifications from the policy-maker. In this setting, criteria of policy are assumed, then intentions, requirements and priorities, perhaps of antagonistic stakeholders, represented. Then, linear programming is used to search for admissible solutions which would provide a coherent index. Interactive scaling is also delineated in order to elicit an institutional index, which is acknowledged by different social actors.