The question arises: do problems of concept-formation in such research differ from those in quantitative social research? It has often been maintained that this is so. While in quantitative social research concepts tend to be pre-formed and fixed (it is argued), in qualitative research they tend to be fluid and emergent. Herbert Blumer's classic paper, "What is wrong with social theory?" (1954), in which he distinguished between definitive and sensitising concepts provides a clear statement of this view.