In these methods, participants vote with their bodies, so everyone can always see who is in which group, and any changes are quick, easy, and obvious.
In the Floor Gallery version, participants stand in groups around the items they like. Use this version when the items to be chosen are fairly large and might take a little time to read – like elevator pitches, idea sketches, or service ads.
In Coraling, they form lines and branches like coral growing from an item on a wall. Use this variant for clusters of sticky notes, or anything which cannot be easily removed from the wall.
Use these methods when you want to decide which ideas to work on next, and quickly form new workgroups. Use them to split up the group for the next task of a workshop, not to form long-term teams for a project.