# Northern Illinois University Teaching with Blackboard Faculty Development and Instructional Design Center

## Blackboard FAQ: Weighted Grade Options

### Is there a way to include the extra credit in weighted total calculation?

Yes. A weighted total score involves calculating the percentage of the points possible for the item in relation to the total possible points the student has earned. For example, you can grant students a certain percentage of increase of their total course grade as extra credit for completing a particular task or set of tasks. Here is one possible solution to assigned extra credit while weighting grades.

Create an item in the Grade Center that has a "points possible" value of 1. Then, weight the item or the "Extra Credit" category so that it is worth 1 percentage point of the total grade. Give all students 1 point in the extra credit item for simply being in the course, thus avoiding any complaints that only 99% was possible without the available extra credit. Then, give students deserving of extra credit additional points in the extra credit item corresponding to the number of percentage points increase that you desire to award.

### I tried using weighting in my course gradebook but have decided not to use it. How can I turn off weighting?

To remove weighting from the Grade Center, simply delete the Weighted Total column and use the Total column. Note that the Weighted Total column cannot be deleted if it set to be the External Grade; in this case, first set the Total column to be the External Grade by clicking the Action Link in the Total column and selecting Set as External Grade.

If the Total column has already been deleted, a new one can be created.

1. Click Create Calculated Column
2. In the menu, click Total Column
3. On the Create Total Column page, give the column a Name, and select which columns should be included in the Total
4. Click the Submit button

### What is the difference between proportional weighting and equally weighting categories for weighted grades?

Proportional vs. Equal weighting is a setting when you weight by category. It only makes a difference if you have columns with different points possible in the same category (e.g. a Discussion category with columns worth 5 points and columns worth 10 points). If all of the columns in the category are equal, both settings work the same way.

When you have categories of differing values, Equal Weighting converts the columns to percentages and averages the percentages to get the category composite grade. It essentially gives each item equal weight when determining the composite grade. Proportional weighting calculates a category composite grade by adding the raw scores and dividing by the total points possible. It retains the proportional weight of each item, so items with a larger value have more effect on the composite grade.

For example, consider two assignments in a category, one worth 5 points and the other worth 10 points. Assume the student gets 5 points on each assignment.

Equal weighting: 5/5 and 5/10 = (100% + 50%) / 2 = 75% (or you can think of converting it to equal Points Possible: 10/10 and 5/10 = 15/20)
Proportional weighting: 5/5 and 5/10 = 10/15 = 66.7%

The category composite grade is then weighted according to the percentage you indicated for the entire category and combined with the other columns or categories you have included in the Weighted Total.

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Last Updated: 07/25/2011