Qualitative research utilizes methods that seek to discern the quality — as opposed to the quantity — of its subject. It is, therefore, more often concerned with explaining the why and how of a phenomenon rather than the what, when and where.
Qualitative research methods are most often utilized in fields such as anthropology, the humanities and sociology, although each of these fields can be studied through quantitative methods as well. Since this type of research is exploratory and focuses on discerning the why of things, such as human behavior, rather than the what of the natural world, it is often criticized for being too subjective. Many make the counter-argument, however, that since qualitative methods are hypothesis generating, they are not only just as valuable as quantitative methods but necessary for the production of theoretical models which come to inform the direction of quantitative research methods.
Data collection and analysis is another way that quantitative and qualitative research differ. In qualitative research, data samples are usually not collected through random selection but rather purposive reasoning, which is to say they are chosen for how well they typify the characteristics of a certain class. For example, a qualitative study on racial inequality will not likely concern itself with affluent minorities or the entire population of a minority, but rather, it might focus on depressed areas where minorities are most prevalent. This approach is chosen because qualitative researchers are not concerned with discerning the quantity of people in a minority class, but rather the quality of life for minorities who are affected by inequality.
The researcher's role in interpreting the meaning of data is more centralized in the qualitative approach than it is in quantitative methods, which ideally seek to make purely empirical observations devoid of perspective. In sharp contrast, qualitative researchers must reflect upon their research and make the reasoning behind the interpretations of their data explicit in their analysis.
Qualitative research is thought especially valuable in circumstances where quantitative data does not account for a particular phenomenon. For example, while economics frequently concerns itself with collecting concrete information, like statistics and financial data, it can be said to be flawed because it ignores the humanistic and psychological aspects of the people that are a key component. This human component requires a qualitative understanding, which leads to the development of such concepts as "consumer confidence."
An important variable to consider when analyzing the dependability of qualitative research is validity. It is important to consider how a conclusion was reached, and whether it really represents a dependable and realistic interpretation of its subject. It may or may not be pertinent to ask whether or not a conclusion is reproducible, or whether it was affected by bias. One should also consider whether data from qualitative studies is well reasoned and the extent to which it accounts for a substantial majority of the available data.