We're working on the next release of our card sorting analysis software, SynCaps V3 and need a few sites to try out the new 'nested groups' feature on face-to-face, paper-based projects. This allows the kind of hierarchical sorting that many want to do but that few tools support, for example:
Vegetables (group level 1)
-Root Vegetables (group level 2)
--Potatoes (group level 3)
---White Potatoes (item)
---Sweet Potatoes (item)
and so on.