Re-viewing the concept of saturation in qualitative research

The term saturation is used ubiquitously in reports of qualitative research. The term is often used, however, as a throw-away line, sans definition, rationale, or explanation of the process. Consequently, there remains a question about what is meant when saturation is used.

The concept of saturation originated in grounded theory. Achieving theoretical saturation is one of the tenets of grounded theory. Over time, this specific and singular term has migrated to a general term that reflects various types of saturation such as code, data, theme, and meaning saturation. There is a lack of clarity among saturation types and a lack of transparency in reporting what is meant by saturation and how it was achieved. There is also a question about the relevance of saturation to qualitative methodologies outside grounded theory.

In seeking to raise awareness of the issues surrounding the term saturation, in this discussion paper we offer a synopsis of the history and evolution of the term saturation, address the current conundrum about saturation in qualitative research, and examine the use of saturation in qualitative articles published in the six nursing journals with the highest journal impact factors. This re-view reflects the need to critically assess the status of saturation as it is used in nursing journals. Better definitions of terms are needed to assure consistency in language that will enhance understanding for the end user of qualitative research reports. Those conducting and assessing qualitative inquiries need clear understanding of what is appropriate for each qualitative methodology—saturation does not apply to some qualitative approaches.

Mentorship and teaching are at the heart of the saturation issue. Finding a mentor who is a solid methodologist may require nurses to reach out to individuals in other disciplines such as sociology, psychology, or anthropology. In the absence of a mentor, investigators conducting qualitative inquiry are urged to become well-versed in the methodology they believe is best suited to their question by turning to original sources written by well-trained methodologists. It is imperative that students who may become educators or researchers who then become reviewers and perhaps journal editors have a solid understanding of key qualitative concepts such as saturation.