In the "Generating Insights" phase of a retrospective, the "Group Mind" activity provides a way for teams to discover where their thinking converges and quickly identify common concerns.
The retrospective leader (RL) helps the team form three or four small groups of team members--pairs or triads, depending on the size of the team. Each small group takes no more than eight to ten minutes to brainstorm all the issues (or ideas for action) facing the team and write each one on a separate sticky note. The retrospective leader challenges the sub-groups to go for quantity of issues over quality. Every issue they can think of should appear on a group sticky note.
Serially, each group offers one issue on a sticky note. The RL asks whether any other group has the same or similar issue and places those sticky notes in a row on the flip chart page or whiteboard. Then another group offers an issue for matching and posting. The process continues, moving from group to group until the team has posted all the issues.
When all groups have reported all their issues, the RL highlights which issues came from all the groups. These are the "group mind" of the moment. As the team moves into the "Deciding What to Do" phase, they focus their ideas for actions on the common issues.
The agile coach or scrum master makes a record of the remaining issues, as the team may converge on one of them as the "group mind" at a future retrospective.