Single vs. comparison
Talk to one persona, or run two side by side to compare their answers.
A regular, one-on-one conversation with a single persona. Use this for open-ended exploration, or when you already know exactly which customer segment you want to understand.
Why it matters later
The format you choose carries through to the rest of the workflow: analyzing an A/B interview produces a comparison insight (with a side-by-side view and a highlighted preferred answer), while a single interview produces a standard insight. See From interview to insight.