[Qualitative methods in empirical health research. 1. Scientific theory and application]

This is the first in a series of articles intended to present theoretical and practical aspects of qualitative research within the health sciences. Various paradigms related to qualitative research are discussed, and it is argued that the constructivist paradigm, as outlined by Guba & Lincoln, may be appropriate for the purpose of qualitative health research. The philosophical schools of phenomenology and hermeneutics, and their importance to the constructivist paradigm, are briefly discussed, and finally the relationship between qualitative and quantitative research.