I would call the first one “dialogue” and I’m not sure a debate format is conducive. Unless it’s sort of a mock debate where both parties are taking sides that they aren’t convinced are completely true. And I’m not mocking that, it’s a valuable exercise. Debate is better designed for two opposing parties who have considered each others’ arguments and have reached conclusions. The learning then occurs in those who are listening. This is different than learning from a single expert who can present only evidence that supports their conclusion.
Dialogue requires listening and suspending judgment. Each side is asked to consider the other’s argument and only explain why it doesn’t fit with their experience, not why they think the other person is wrong or some probability of error or logical misstep. I watched the Intelligence squared debate on GMO foods for instance. That was the proposition: “GMO foods” for or against. Against it in part was that the GMOs hadn’t delivered on original expectations, instead their primary success has been Round-up ready crops that have encouraged more herbicide use leading to dangers for butterflies and bees. The for argument was, that’s conflating GMO food with other things. Logically the “for” side was absolutely right, but of course that shut down a whole discussion that maybe we should be having.