In its research and service activities, GESIS addresses methods of social science survey research. The staff are acknowledged experts in different areas of survey design, sampling, and data collection. One of GESIS’ key offerings to the social science research community is an advisory service for scientists on methodological aspects of the organisation and implementation of survey projects. The web offering GESIS Survey Guidelines presents the main topics of GESIS’ advisory service in the form of contributions that address certain methodological aspects of the implementation of surveys or topics on which written documentation is frequently requested during individual consultations. The GESIS Survey Guidelines are organized into three parts: "Survey Operations," "Survey Instruments," and "Survey Statistics".