For Gradebooks that use Categories & Weights, the overall Course Grade is miscalculated if you excuse a grade.
(If not using Cats & Weights, course grade calculates correctly when you excuse a grade.)
Steps to replicate:
- Set up a Gradebook with Categories & Weights, such as:
- Homework = 40%
- Exams = 60%
2.Create a few items in the Homework category, such as:
- HW1 = 100 pts
- HW2 = 100 pts
- HW3 = 100 pts
3. Just to be thorough, create one or more items in the Exams category, such as:
- Exam 1 = 100 pts
4. Assign a student the following grades:
- HW1 = 100 pts
- HW2 = 80 pts
- HW3 = 60 pts
5. Notice that the Course Grade is 80%, which is correct.
6. Excuse the student's grade for HW3 (which has a score of 60), by clicking the dropdown arrow in the cell and choosing "Excuse/Include Grade". The Course Grade doesn't immmediately update – click GRADEBOOK at the top to refresh the page to see the updated calculation.
7. Notice that the Course grade is now 60%, which is incorrect – it should be 90%.
8. Notice that the Weighted Average Column for the Homework category displays 90%, which is correct. (Group by Category must be ON to see this.)
9. Enter a grade for Exam 1, such as 100. Notice that the Course Grade is now 84%, which is incorrect. It should be 96%.
Note: If you go into Settings, and change to "Categories only" or "No categories", you will see that the Course Grade is correctly calculated.
When you excuse a grade, two different weighted averages are being calculated for the category. The one displayed in the category's Weighted Average column is correct – but a different, miscalculated average is used in the Course Grade calculation. This miscalculated average wrongly includes the point value for the excused item in the denominator, like so:
(HW1 grade + HW2 grade) / (HW1 pt value + HW2 pt value + HW3 pt value)
The correct formula should be:
(HW1 grade + HW2 grade) / (HW1 pt value + HW2 pt value)