Note that you can link Pobble to your MIS (SIMS, Arbor, Scholarpack, etc.) to automate this process.
Groups can be used to easily retrieve students to generate statistics, or to include them in your lessons. On your pupil list, you can assign as many groups as you like to any student. If you have linked Pobble to your MIS, a number of groups will be automatically created based on the information available.
In case you are moving an entire group into a new group ("Mr Johnson's class" is now "Ms Beckett's class") you can also just rename the group.
By default, groups are visible on your school page, so that parents and other users can easily find the work they're interested in. You can change this to a private group (only visible to you) via the action button.