A distinction between pure and applied science is drawn in every scientific field. Pure science is a search for knowledge, without primary concern for its practical use.
Applied science is the search for ways of using scientific knowledge to solve practical problems. A sociologist making a study of the social structure of a slum neighbourhood is working as a pure scientist if this is followed by a study of how to prevent delinquency in a slum neighbourhood this is applied science.
Practical applications of sociological knowledge have become quite common. Sociologists are employed by corporations, government bureaus and social agencies often in evaluation research but sometimes in administration. Sociologists are often consulted by legislative committees in preparing new legislation. While the political clout of opposing interest groups may be the prime determinant of social policy decisions, the policy recommendations of social scientists are a significant factor in the legislative process.