The GSS applies a proportional sampling technique. The method consists on dividing the total population (US adults over 18), which is a finite number, into subgroups. Afterwards, random sampling is conducted in each subgroup. The aim is to gather subjetcs coming from urban areas, suburbs and also rural regions.
It is a ongoing survey to US households. Interviews are preferably celebrated in person or, if is not possible to schedule them like that, the telephone is used instead. Questions aim to collect information on a great variety of topics: demographic information, behavioural patters such as voting or group memberships, personal psychological evaluations (measuring of happiness, life satisfaction), spending patterns, beliefs and opinions on public issues such as race relations, gender roles, how to punish crime, for or against abortion, etc.
Results are freely available online and are a very valuable resource for students, scholars, social scientists and policymakers.