It is probably a good idea at the end of each school year to reset your course. With resetting your course you can delete grades, quiz attempts, forum posts, and pretty much anything else that your students added to your course from the beginning of the year. Below is a tutorial on how to reset your course so that you get a fresh start in the upcoming school year.
1. Make sure you are logged in as the course creator for you Moodle class. It might reset as well if you are the course teacher, but I am not sure. Once you are logged into the course you should find under you administration options a link that says "Reset." Click it.
1a. If you scroll all the way to the bottom of your "Moodle" page you can choose the "Select default" button, which will do most of the check boxes for you. This is the option that I use when resetting my Moodle courses. If you want to see what they other options are for then keep reading the tutorial.
2. You now have a whole slew of options to play with. You can see under "General" that I can delete calendar events, logs and notes. Just select the items you want deleted.
3. Most teachers are going to want to reset at least the grades from the gradebook so make sure you check the "Delete all grades" option.
4. If you have created groups of students the year before you can get rid of those groups.
5. The "Roles" section is also one that for sure you want to reset. Make sure that you unenrol "Students" by selecting them.
6. If you students turned in or uploaded documents into the Moodle environments, then make sure you select the "Delete all submissions" option under the "Assignments" section.
7. Delete the chat history if you want.
8. I never do forums in my class, but if you do, just pick the options that apply to your class.
9. If you had your students add to the course glossary, then use this section to delete their entries.
10. The last option is to delete all quiz attempts. Make sure you choose this option as well.
11. Just click the "Reset" course once you are finished down at the bottom of the Moodle page.