Online Big Data (OBD) are seen in sociological research as quantitative information about web-sites visitors, their internet activities, individual preferences and interests. The paper summarizes capabilities of analytic platforms to collect, process and preserve (store) big data. A system is offered related to their indices used in sociological analyses. Considering that fact that construction of methodology for analyzing big data is in its initial stage, introduction is discussed of a conceptual methodological scheme for OBD analysis, as well as of meta-data monitoring for realizing technical principles of operation and regular introduction of necessary corrections, of automation of big textual massive and of standardizing web-measurements.