Sociology is the scientific study of social behaviour, including its origins, development, organization, and institutions. It is a social science that uses various methods of empirical investigation and critical analysis to develop a body of knowledge about social order, social disorder and social change. Many sociologists aim to conduct research that may be applied directly to social policy and welfare, while others focus primarily on refining the theoretical understanding of social processes. Subject matter ranges from the micro level of individual agency and interaction to the macro level of systems and the social structure. The traditional focuses of sociology include social stratification, social class, social mobility, religion, secularisation, law, sexuality 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 further subjects, such as health, medical, military and penal institutions, the Internet, education, 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, more recent decades 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, lawmakers, administrators, developers, business magnates, managers, social workers, non-governmental organisations, non-profit organisations, 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.