Definition

Saturation

The point in qualitative data collection where additional interviews or observations stop yielding new codes, themes, or insights.

Saturation is qualitative research’s stopping rule: collect until the data stop teaching. Empirical studies of homogeneous samples typically find code saturation around 9–17 interviews, but the number depends on sample diversity, question breadth, and analysis depth.

What convinces reviewers is not a magic n but documentation: show that late interviews produced no new codes (a saturation table works well), and distinguish code saturation (no new labels) from meaning saturation (no new understanding of existing ones).