Learn · Qualitative methods
Saturation is not a number of interviews. It is two different kinds of "enough", and most papers only reach the shallow one. Here is the difference, how to decide when to stop, and how to document it so a reviewer accepts it.
After this guide you will be able to:
Code saturation is the point where no new topics appear. You keep hearing the same issues, the same observations, the same surface-level problems. It answers a useful question: have I heard everything? It does not answer the deeper one: do I understand it?
Meaning saturation is when you understand why participants act as they do, and how the themes relate to each other. It needs nuance, variation, and context. So it usually takes more data than code saturation, and here is the trap: you can reach code saturation without ever reaching meaning saturation. The topics stop being new long before you understand them.
There is no fixed number. Saturation depends on how rich and how repetitive your data are, not on a target of 12 or 20. So do not pre-commit to a number. Start with a focused question, estimate from similar studies, and stay flexible as you go.
The work is to analyse as you collect. Track new codes in a saturation table, one row per interview. When the last few interviews add nothing substantial and your categories are well developed, you can justifiably stop. Then write down how you decided: how many new codes each interview added, and why you stopped there.
The honest version. "Saturation was reached" is a claim, not evidence. The record behind it is the evidence: the question, the saturation table, the new codes per interview, the reason you stopped. That record is more rigorous than the sentence, and it is what a careful reviewer actually wants to see.
Say what saturated, and show when.
You wrote "saturation was reached", and a reviewer wrote back: "saturated for what?" That is not sloppiness. The word travels between traditions without its definition attached, so everyone inherits the term and few inherit the rule. The fix is to name what saturated and show the record. MethodVahti helps you justify your sample size and draft a COREQ or SRQR methods section before you collect, so the claim is documented as you go, not reconstructed at review. It checks that your method, your terms, and your written claims line up. It does not decide your themes are right. That stays yours.
See MethodVahtiSee also build a qualitative codebook for the codes themselves, and a short history of qualitative research for where "saturation" came from. More guides are on the Learn page.