I have examined the behaviour of 2 types of activities (Moodle 2):
type #1: activities which are automatically graded: Quiz and Lesson
type #2: activities which can be manually graded (by teacher or student): Glossary and Forum
I am not interested in other types of graded activities, such as e.g. assignment, because participation (i.e. submission) in those attempts cannot be deleted.
What happens when activities of type 1 and 2 have been graded and then a graded "attempt" or "sumbission" or "entry" is deleted (by the teacher) for any reason whatever?
For type #1 activities, the database entry for the activity and the participant (student) is not deleted, but its RAWGRADE value is set to NULL.
For type #2 activities, the database entry for the activity and the participant (student) is left intact. If we take the case of a glossary where students can add entries, and a student entry has been graded by the teacher, and that grade appears in the student's gradebook, well, if the teacher later on decides to delete that student's glossary entry, the grade is not deleted (set to NULL) in the student's gradebook. Which means that a student retains a grade for a submission which no longer exists. Would it not be more logical to adopt, for type#2 activities, the same behaviour as for type #1 activities?
Joseph