Stratified nomic realism

From a realist perspective, the main target of theory oriented empiricalscience may be characterized as the truth about the demarcation betweennomic, e.g. physical, possibilities and impossibilities, called the ‘nomic truth’.In my “Models, postulates, and generalized nomic truth approximation” (2016)I have presented the ‘basic’ version of generalized nomic truth approximation,starting from ‘two-sided’ theories, consisting of models and postulates. Nomictruth approximation becomes, in this way, a process of revising theories, by revising their models and/or their postulates, as more evidence arises. The basicversion of generalized nomic truth approximation is in several respects as simple as possible. Among other things, the basic version does not make a (theoryrelative) distinction between an observational and a theoretical level. Thisraises the question of how, in a stratified set-up, theoretical (nomic) truth approximation relates to observational truth approximation and to increasing empirical success