Creating a formula in the grades formula editor

The Formula Editor enables you to define a formula that calculates a grade item’s value based on other grade items. When you create a formula you specify which grade items you want included in the formula and the relationships between them. An example of a simple formula is one that calculates the sum of a number of grade items. A more complicated formula is one that drops the minimum or maximum value from a set of grade items.

Note If the Formula Editor is turned off at your organization, contact your site administration about getting access to this functionality.

Formula Editor

The Formula Editor is available on the New Item and Edit Item page for Formula items, and the Edit Calculated Final Grade page and Edit Adjusted Final Grade page for the Formula grading system.

Access the Formula Editor
Key Grades Formula Editor components
Grades Formula Editor validation errors
Example grade formulas

Access the Formula Editor

From the Grades List page, click the name of a formula grade item or the Calculated Final Grade.
Click the Edit Using the Formula Editor.

Key Grades Formula Editor components

Formula area

The Formula Area is where the formula text is displayed. The equals sign (=) at the start of the formula cannot be deleted. A cursor shows your position in the formula. Click in the formula area to position the cursor.

Cursor placement

The cursor placement icons are used to move the cursor forwards and backwards in the formula. You can also move the cursor by clicking on the new location with your mouse. There are four options:

Move cursor to start of formula
Move cursor to end of formula
Move cursor back one element
Move cursor forward one element

Grade item parameters

The Grade Item drop-down contains a list of grade items you can insert as a parameter in your formula. You can insert Numeric, Pass/Fail, Selectbox, and Formula type grade items. You cannot reference the formula grade item you are defining (this avoids a circular reference) or a final grade.

The Grade Item Value drop-down determines what value associated with the grade item you want to use in the formula. There are three options:

Points Received The grade the user achieved. E.g., 7 (out of 10 points).
Max Points The maximum points available for the grade item. E.g., 10 points.
Percent The percent grade the user achieved. E.g., 70%.

The Insert Grade Item button inserts the selected grade parameter in the formula.

Insert a grade item parameter in a formula

Select a Grade Item.
Select the Grade Item Value you want to use in the calculation.
Click Insert Grade Item.

Notes

For the weighted system, category and grade item weights are ignored in formula calculations.

Dropped grade items and bonus grade items are calculated the same as other grade items.

Functions

The Function drop-down contains a list of functions that you can use in your calculation formula:

MAX Calculates the maximum (largest) value in a set of values.
MIN Calculates the minimum (smallest) value in a set of values.
SUM Calculates the sum (total) of a set of values.
AVG Calculates the average for a set of values by adding all the values and dividing by the total number of values.
IF Operates as a Boolean statement that returns either the value set as true or as false. You must define the condition (Boolean statement), true (then) value, and false (else) value.
NOT Operates as a Boolean statement that returns the value set as true if the condition is false and as false if the condition is true.

Notes

You can embed functions within functions.

The Start, Next Term, and End icons are used to define elements of a function:

Start Starts the function selected in the Function drop-down list with an opening bracket ({).

Next Term Inserts a comma to separate grade items or parts of a Boolean statement.

End Ends the function with a closing bracket (}).

Insert a function in a formula

Select a Function.
Click Start.
Enter a parameter.
Click Next Term to add another parameter or use the numeric keys and operators to define a condition.
Click End when you are done adding parameters and conditions.

Numeric keys and operators

The right area of the Formula editor contains a number of operators and a numeric key pad to build your formula. These operators are usually used in conjunction with at least one grade item.

Backspace and clear

The Backspace and Clear icons let you delete parts of your formula to make changes.

Backspace Deletes the element to the left of the cursor.
Clear Deletes the entire formula.

Cancel

The Cancel button exits the Formula Editor without saving your changes.

Insert

The Insert button validates your formula and applies it to the grade book item or final grade you are working on. If your formula is invalid, you receive an error message and your cursor moves to the point in the formula that caused the error. The error type displays in red above the formula. See Validation errors for a list of potential errors.

Validate

The Validate option checks if your formula conforms to standard formula grammar. If your formula is valid, a confirmation message displays. If your formula is invalid, you receive an error message and your cursor moves to the point in the formula that caused the error. The error type displays in red above the formula. See Validation errors for a list of potential errors.

Preview

The Preview option lets you check how your formula will calculate grades for the first ten users in your user list. Click Close when you are finished viewing the grades. If your formula is invalid, you cannot preview grades.

Grades Formula Editor validation errors

Error	Description	Examples
Unexpected [token_type] e.g., Unexpected operator	The formula contains a function component in an unexpected location	= 5=/1 = (5+1)2
Unbalanced parentheses	The formula contains an opening or closing bracket without a corresponding bracket	= 5+1)
Missing end of function	The formula contains an unclosed function	= SUM{[Item1.Points], [Item2.Points]
Unexpected function end	The formula contains a closing bracket for a function that does not relate to a function	= [Item1.Points]/2}
Invalid number of operator parameters	The formula contains an invalid number of operator parameters	= [Item1.Points] +
Invalid number of function parameters	The formula contains an invalid number of function parameters	= SUM{} = IF{[Item1.Points]<2,5}
Numeric value expected	A Boolean statement or operator was entered in place of a numeric value	= IF{5<2,1 OR 1,4} = SUM{1 = 2,3,4}
Boolean value expected	A Boolean statement was not entered for a condition	= IF {MIN{4,5},100,0} = NOT{4}
Invalid terminal	The formula contains an incorrectly used terminal	= [Item1.Points] + 3.2.5

Example grade formulas

Scenario 1: Give users who achieved over 75% on all grade items in a category 100% for the category.

= IF {MIN{[Week1.Percent],[Week2.Percent],[Week3.Percent]} < 75, 0, 100}

Scenario 2: Drop the lowest two grades in a set of three grades

= SUM{[G1.PointsReceived],[G2.Points Received], [G3Points Received]} - MIN{[G1.PointsReceived],[G2.Points Received]} - IF{MIN{[G2.Points Received], [G3Points Received]} = MIN{[G1.PointsReceived],[G2.Points Received]}, MIN{[G1.PointsReceived],[G3.Points Received]}, MIN {[G2.PointsReceived],[G3.Points Received]}}

Scenario 3: Fail users who receive less than 60% on either their midterm of final exam.

= IF {MIN{[Midterm.Percent],[Final.Percent]} < 60, 0, SUM {[A1.Percent],[A2.Percent],[G1.Percent],[G2.Percent],[Midterm.Percent],[Final.Percent]}}