Saturation is often referred to in qualitative research reports without a definition of the concept or description of the method or procedures used to achieve it.
This topic has received more attention since the 2009 United States Food & Drug Administration (FDA)’s publication, Guidance for Industry – Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims, a document that addresses the use of patient-reported outcome measurement instruments for the purpose of evaluating medical product marketing claims). Kerr et al. (2010) published an interesting article on assessing and demonstrating data saturation as it relates to this topic.
What techniques are researchers using in practice to provide evidence for “theoretical saturation” in qualitative research (e.g., based on a grounded theory approach)?