If a student told you that they were able to modify test or assignment scores on their end, do not panic. They were just using the “What-If” feature in their own gradebook.
This feature allows students to calculate their total grade by entering hypothetical grades for both graded and yet to be graded items. It helps to estimate how their grades will be effected by upcoming or resubmitted assignments.
Entering the hypothetical scores will not effect the grades that instructors entered on the “Grade” page in Canvas. Students can easily revert the grades back to the actual scores anytime.
To see how it works for students, check out the instructions on “How do I approximate my assignment scores using the What-If Grades feature?”. You may also test the feature as a student by using “Student View” on the course home page.