Click on the Administration block on the left side of your Wattle course and select Gradebook Setup.
The Gradebook Setup Page appears.
To lock individual items, find the individual item > go to the "Edit" menu under Actions > select "Edit Settings" from the drop-down menu.
To lock all items in a category, go to the "Edit" menu for the category > select "Edit settings" from the drop-down menu.
In the Edit grade item settings, tick the "Locked" box and this will prevent editing for the individual items.
If you are editing the settings for the category via the Edit tab under Actions, the same action applies, and it will lock all items in the category.
Note: When the padlock is locked, no assessment items can be changed.
If you subsequently wish to change a grade, you will then need to click on the locked icon to unlock it in order to change that grade.
Scroll to the bottom left side of the Grader Report screen and click Save changes.