Data collection and sampling in qualitative research : does size matter?

In this editorial we discuss issues relating to gaining quality data from individual and focus group interviewees. The primary strength of qualitative research is its potential to explore a topic in depth (Carlsen & Glenton 2011). Qualitative research is epistemologically grounded in social constructivist, symbolic interactionist, or other interpretive conceptual frameworks, or perspectives. It can traverse a range of information gathering and analysis methods, which have an impact on how participants are selected, and when data collection should stop.