There is an interesting and relevant aside to mention about this group, having to do with expectations and citizenship. For reasons I won't go into, this team of business analysts thought they were supposed to work in the XP style and that XP prohibited them from writing things down.
Notice four things about their situation:
1. They misunderstood XP. It does not forbid people to write things down.
2. Their citizenship was so strong that rather than be poor citizens and write down their thoughts on the domain model, they chose to be good citizens and not write down their business model at all!
3. Actually, they knew that the project wouldn't succeed if they really wrote nothing down. So they each clandestinely wrote pseudo use cases and other notes, which they passed to the programmers. They still did not create a domain model for themselves.
4. By writing down those notes, they subverted their own (mistaken) interpretation of the official process. I find this situation particularly interesting, because they were at war with themselves about whether to be good citizens and follow the process (at the expense of the project) or to be good citizens and protect the project (by violating the process).
What was significant in the end was that they posted an information radiator on the corridor wall, on which they scribbled individually and as a group, to give their thoughts and decisions some stickiness.
I feel like I have been in this situation before. I want to do the right thing, but I don't know what the right thing is. I often wonder if I am shooting myself in the foot by trying to be too strict with my attempts to follow the XP recommendations. I guess it would be helpful to have an Agile coach to talk to.