The term qualitative research refers here to social research based on field observations analyzed without statistics. The subjects may or may not know that they are being observed for social research purposes. The degree to which observes participate actively in the lives of the subjects may vary.
However, the term participant observation often stands as a synonym for qualitative research, and it implies some involvement in the observed setting. Qualitative research always takes place in the field, that is, wherever the subject normally conducts their activities. For this reason, qualitative research often goes by the name of field research.