Qualitative research is research which does not depend upon numerical measurement.

In statistics, qualitative analysis refers to procedures that use only dichotomous data – that is, data which can take only the values 0 (zero) and 1 (one). These techniques are suitable where events or entities can only be counted or classified rather than measured. The techniques themselves are, of course, numerically based.

In the social sciences, qualitative research has acquired the rather different meaning of research where no attempt is made to measure, count, or classify, but rather the aim is to capture the full complexity of human or social phenomena, by analyses that focus on the details and nuances of people's words and actions. The techniques used were first developed in ethnography but are now used in most social sciences. In psychological and some other social sciences, when formal qualitative techniques became available in the 1990s, the decision to use them often reflected a philosophical or ideological belief that quantitative measures were inappropriate or inadequate in a human science (see qualitative psychological research). Nowadays, however, most social scientists would see qualitative and quantitative techniques as complementary (see multimethodology, each being appropriate to different phases of a research project.

See also: quantitative research