Sociologists study the ways that social structures and interactions shape human life. We seek to understand the full range of social institutions and practices, from couples and small groups, to social organizations such as businesses and government agencies, to communities, cities, and nations.Our methods of research are diverse, ranging from the quantitative analysis of large surveys to qualitative approaches such as in-depth interviewing, participant observation, and historical investigation. Indeed, diversity in its subject matter and its methods of research is one of sociology's most distinguishing features. Because sociologists study social interaction in a broad array of contexts, we use whatever method is appropriate for the particular question being posed.Sociological ideas and methods are used by policy makers, political analysts, and social critics. Many of our concepts have become a part of our common culture and everyday language. Concepts such as the self-fulfilling prophecy, conspicuous consumption, WASP, social mobility, modernization, and in-groups and out-groups were all originally coined by sociologists.Similarly, sociologists were studying important topics such as social inequality, race relations, gender discrimination, and sexual diversity long before these became issues of concern among policy makers and in popular culture. Many modern research techniques, such as polling and survey design, were also pioneered by sociologists.