Empirical social research has a significant number of data sets, which are systematically accumulated and utilized mainly through the Social Science Data Archives for secondary analysis. These are data produced on a case-by-case basis in individual surveys of a larger or smaller scale, characterized by a limited time depth and represent aspects of each country's social reality. Although not designed for this purpose, they are the raw material for comparative research, working more as a collective memory. Research infrastructure plays a crucial role both in the subsequent homogenization of available data sets and in the design of comparative research from the outset.