This reference explains how formula grade items evaluate exempt or null values when using mathematical operators and comparisons. Use this article if you are building or troubleshooting complex formula grade items.
If you want to understand how exemptions affect grade calculations in general, see Understand how exemptions affect calculations.
Before you begin
Formula grade items treat exemptions differently than ungraded items.
- Exemptions are evaluated as null values.
- The Treat Ungraded as 0 setting does not apply to exempted grades.
- Drop Ungraded Items affects only ungraded items, not exemptions.
- Cascading nulls: If a formula grade item evaluates to null due to an exemption, any other formula grade item that references it also treats that value as null.
These rules apply whenever an exempted grade item is referenced directly or indirectly by a formula grade item.
Formula evaluation rules
The following table summarizes how formula grade items evaluate exempt or null values for common operators.
| Operation |
Evaluation rule |
Result |
|---|
Math (+, -, *, /)
|
Addition/Subtraction: One side is exempt and the other has a value |
Returns the non-exempt value |
| Addition/Subtraction: Both sides are exempt |
Null |
| Multiplication/Division: Either side is exempt |
Null |
Equality (=)
|
Both sides are exempt |
True |
| One side is exempt and the other has a value |
False |
Inequality (<>)
|
One side is exempt and the other has a value |
True |
| Both sides are exempt |
False |
Comparison (>, <)
|
One side is exempt |
False |
Comparison (>=, <=)
|
Both sides are exempt |
True |
| One side is exempt and the other has a value |
False |
Examples
The following examples show how formula grade items behave when one or more referenced grade items are exempt.
| Formula |
Scenario |
Result |
|---|
| Quiz1 + Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
90 |
| Quiz1 - Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
-90 |
| Quiz1 + Quiz2 + Quiz3 |
Quiz1 is exempt; Quiz2 = 80; Quiz3 = 90 |
170 |
| Quiz1 × Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
Null |
| Quiz1 ÷ Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
Null |
| Quiz1 = Quiz2 |
Both grades are exempt |
True |
| Quiz1 <> Quiz2 |
Both grades are exempt |
False |
| Quiz1 <> Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
True |
| Quiz1 > Quiz2 |
Quiz1 is exempt; Quiz2 = 90 |
False |
| Quiz1 >= Quiz2 |
Both grades are exempt |
True |
| Quiz1 >= Quiz2 |
Quiz1 is exempt; Quiz2 = 80 |
False |
| FinalFormula = MidtermFormula + Quiz1 |
MidtermFormula evaluates to Null; Quiz1 = 85 |
85 |
| FinalFormula = MidtermFormula × Quiz1 |
MidtermFormula evaluates to Null; Quiz1 = 85 |
Null |
Best practices
- Keep formula grade items as simple as possible.
- Prefer calculated grade items over formula grade items whenever they meet your grading requirements.
- Test formula grade items before releasing grades to learners.
- Use exemptions instead of placeholder grades when learners are excused from work.
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