The Group selection tool allows users (students) to enrol themselves (sign up) into groups. Limits can be placed on the number of users in each group. Open and close times can also be set.
The Group selection tool means student choose their group (based on whatever group categories are set up). This approach can give students a sense of control over their learning. Group selection could be used so that students can choose:
a time/day that suits them to do lab/field work
a subject/activity that interests them (regardless of who they will be working with) – this might work particularly well for project or inquiry-based learning