Assign the students to their groups, and assign the tutor to the same groups. The tutor should then be able to pick just their group from the assignment grading page to download just the assignments for their group and grade just the assignments from their group.
http://docs.moodle.org/en/Groups
Why use groups?
- You are a teacher in a course where you have several classes and you want to filter your activities and gradebook so you only see one class at a time.
- You are a teacher sharing a course with other teachers and you want to filter your activities and gradebook so you don’t see the students from your colleagues’ classes.
- You want to allocate a particular activity or resource to just one class or set of users and you don’t want others to see it. See Groupings.