I think you’re right on this. After about 5 interviews per customer segment, it’s possible to start seeing trends in the problems and behaviours stated by members of each segment.

That can help refine and narrow the customer segments, or personas, that were assumed initially.

In my experience it was necessary to conduct more interviews than the initial 5 once a customer segment seemed promising. Generating a wealth of qualitative data within that customer segment was crucial to clarifying the assumptions I had made about them.

I see where you’re coming from, and I’ll add a clarification to the article!

Thanks so much for pointing it out, and for reading! :)