From the 17th century onwards, the rise of science raised the question of how we know what we know (Bryman, 2004). Nineteenth century thinkers such as Auguste Comte, Karl Marx, and Emile Durkheim, believed society could be studied in the same way as the natural sciences, a view known as positivism. Max Weber disagreed with them and said social phenomena were not the same as natural ones, believing society was driven by people's behavior that needed to be understood, a view known as interpretivism.
Positivism and interpretivism are the two main branches of social science research, and each of the associated disciplines of the area--economics, criminology and psychology--in the main uses one or the other, or occasionally both approaches, in research. Positivism works on the gathering social facts while interpretivism seeks to understand people's actions. These are respectively referred to as the quantitative and qualitative approaches to research.
Positivisim is a quantitative approach to social science research, where facts such as a person's gender are noted down and counted. The researcher has a question or hypothesis that he or she wishes to gather data on to see if the hypothesis is correct, normally using survey research. An example of survey research is to find out why people voted in a certain way. The researcher uses questions relating to how a respondent might feel about things like immigration and what income group they are in as indications of certain political leanings. Questions are carefully constructed so that answers give the most accurate picture of what is going on. The data is put into a computerized statistical program that analyzes the numbers to see what they mean.
Interpretivism is a qualitative approach to research. Qualitative researchers also have questions and ideas that they investigate using in-depth interviews with people, or they may become a participant observer in a hospital or school setting. Most qualitative projects investigate small groups of people as numbers are a lot less important for them than for quantitative researchers. The researcher might evaluate how well nurses relate to patients in their care, or try to find out why some women stay with violent men. The researcher then takes the words, behavior and sometimes pictures of people and analyzes them through the major concepts found in the data. Qualitative analysis is time-consuming as it involves trying to understand what the researcher finds in her research.
According to Bryman (2004), the approach someone takes to social science research depends on what he is looking for. In the past, positivism and interpretivism were very different approaches, but that is less true now. Today more people undertake research using a mixture of both methods, often starting with a qualitative approach and interviews, then collecting quantitative data to test out emerging concepts and theories--what Strauss and Corbin refer to as "theoretical sampling."