The traditional focuses of sociology include social stratification, social class, social mobility, religion, secularization, law, sexuality, gender, and deviance. As all spheres of human activity are affected by the interplay between social structure and individual agency, sociology has gradually expanded its focus to other subjects, such as health, medical, economy, military and penal institutions, the Internet, education, social capital, and the role of social activity in the development of scientific knowledge.
The range of social scientific methods has also expanded. Social researchers draw upon a variety of qualitative and quantitative techniques. The linguistic and cultural turns of the mid-twentieth century led to increasingly interpretative, hermeneutic, and philosophic approaches towards the analysis of society. Conversely, the end of the 1990s and the beginning of 2000s have seen the rise of new analytically, mathematically, and computationally rigorous techniques, such as agent-based modelling and social network analysis.
Social research informs politicians and policy makers, educators, planners, legislators, administrators, developers, business magnates, managers, social workers, non-governmental organizations, non-profit organizations, and people interested in resolving social issues in general. There is often a great deal of crossover between social research, market research, and other statistical fields.
Sociology is distinguished from various general social studies courses, which bear little relation to sociological theory or to social-science research-methodology. The US National Science Foundation classifies sociology as a STEM field.
Sociological reasoning predates the foundation of the discipline. Social analysis has origins in the common stock of Western knowledge and philosophy, and has been carried out from as far back as the time of ancient Greek philosopher Plato, if not before. The origin of the survey, i.e., the collection of information from a sample of individuals, can be traced back to at least the Domesday Book in 1086, while ancient philosophers such as Confucius wrote on the importance of social roles. There is evidence of early sociology in medieval Arab writings. Some sources consider Ibn Khaldun, a 14th-century Arab Islamic scholar from North Africa (Tunisia), to have been the first sociologist and father of sociology (see Branches of the early Islamic philosophy); his Muqaddimah was perhaps the first work to advance social-scientific reasoning on social cohesion and social conflict.