Last update:
21-Sep-2006

In the field of health sciences, only during the last decades has there been a growing interest in the applicability of qualitative research methodology. Concurrently, a debate began about the scientific value of qualitative studies and the process and evaluation criteria for testing the objectivity of qualitative findings. For the quantitative approach, the "truth" is unique and undisputable, whereas the qualitative researchers regard scientific knowledge emerging from specific data and its accompanying validity as dynamic within a changing environment. Also, the scientific criteria related to qualitative research differ from those applied in the quantitative approach. The concepts of reliability and validity, of the latter, pertain also to the qualitative approach, although they are defined differently, because the nature, the objectives and the research questions are different. In qualitative studies, reference is made to concepts such as stability, reproducibility, credibility, authenticity, applicability, transferability and fittingness, without attempting to generalize the conclusions to a larger population. The purpose of this paper is to motivate researchers to adopt the qualitative approach for investigating, in depth, complex phenomena in the health care domain, and to assist the researcher in implementing this approach and the external reviewer in assessing the research process and the value of the qualitative study. This is accomplished through detailed discussion of the new methods for formulating research questions and the basic principles for evaluating qualitative thinking without bias.

Key words: Evaluation, Health sciences, Qualitative research, Reliability, Validity.