Six years ago when I started experimenting with ensemble testing, one of the key dynamics I set a lot of experiments around was *taking notes* and through that, *modeling the system*.
At first, I used that notetaking/modeling as a role in an ensemble, rotating in the same cycle as other roles. It was a role in which people were lost. Handing over document that you had not seen and trying to continue from it was harder than other activities, and I quickly concluded the notes/model were something that for an ensemble to stay on common problem, this needed to be shared.
I also tried a volunteer notetaker who would continuously be describing what the ensemble was learning. I noticed a good notetaker became the facilitator, and generally ended up hijacking control from the rest of the group by pointing out in a nice and unassuming way what was the level of conversation we were having.
So I arrived at the dynamic I start with now in all ensemble testing sessions. Notetaking/modeling is part of testing, and Hands (driver) will be executing notetaking from the request of the Brains (designated navigator) or Voices (other navigators). Other navigators can also keep their own notes of information to feed in later, but I have come to understand that in a new ensemble, they almost never will, and it works well for me as a facilitator to occasionally make space for people to offload the threads they model inside their heads into the shared visible notes/model.
Recently I have been experimenting with yet another variation of the dynamic. Instead of notes/model that we share as a group and use Hands to get visible, I've allowed an ensemble to use Mural (post-it wall), on the background to offload their threads with a focus on mapping the future they are not allowed to work on right now because of the ongoing focus. It shows early promise of giving something extra to do for people who are Voices, and using their voice in a way that isn't shouting their ideas on top of what is ongoing but improving something that is shared.
Early observations say that some people like this, but it skews the idea of us all being on this task together and can cause people to find themselves unavailable for the work we are doing now, dwelling in the possible future.
I could use a control group that ensemble together longer, my groups tend to be formed for a teaching purpose and the dynamics of an established ensemble are very different to the first time ensemble.