I've invited potential users to come in and look at our portal. These people only know what we do, but have never seen the UI of our portal. We will tell them about what we do and after that we can show them visuals of our portal, but not a working demo yet. I want to let them do some card sorting to help with the information flow and architecture.
I've asked a more general question about it here.
Should potential users do card sorting before or after seeing the portal for the first time?
Doing the card sorting after might cloud their vision about the cards, but doing the card sorting before might not give the potential users enough context on what they are doing.