Abstract. The fundamental system of criteria for strong and weak polarization responses of ordered objects and systems is considered. It is shown that the weak responses have important properties of linearity (proportionality) and additivity. As an example, the responses of magnetically ordered materials, optical crystals and ensembles of magnetic nanoparticles are considered. When scanning laser probing of the modified leucosapphire crystals, oscillations of weak polarization responses in laser radiation scattered on texture of crystals are recorded. Investigations of magnetic fluids polarization responses have shown their high sensitivity to introduction of coagulating impurities and to processes of agglomeration of magnetic nanoparticles.