Gradebook2 FAQ: What factors affect course grade when I use weighted categories?
posted this on May 15, 2012 08:03 AM
If you have set up Gradebook2 for weighted categories, keep in mind that several factors can affect the course grade--and in ways you may not have anticipated!
How unscored items can affect course grade to date In Gradebook2, a course grade is always calculated, even if you have not entered scores for all items. This “course grade to date,” however, may not accurately reflect your final weighting strategy. (For more information, see How is course grade calculated for weighted categories?)
When you have not graded every item in the gradebook, the CLE must make some adjustments to weights. To calculate this “course grade to date,” the CLE will:
Ignore categories in the gradebook with no scored items, and proportionally increase the weights of categories with scored items to equal 100% of the gradebook.
In a category, ignore unscored items and proportionally increase the relative weights of the scored items to equal 100% of the category.
Keep in mind that you will not see these weight adjustments displayed in the gradebook. Consider the following example, in which one category contains no scored items:
Next, consider this example, in which only two items in a category are scored:
Calculating item weight: To better understand how these weight adjustments can affect course grade, let’s first review how an item weight in gradebook gets calculated:
relative weight in category × category weight in gradebook = item weight in gradebook
Calculating weighted score: Next, let’s review how the weighted score for an item is calculated in a points-based gradebook:
earned points ÷ possible points × item weight in gradebook = weighted score for item
Any adjustments to relative weights and/or category weights will change an item’s weight in the gradebook--and therefore its weighted score. So, the weighted score of an item when all items are graded will probably be different from its weighted score when all items are NOT graded.
Let’s say you have added an extra credit item to a category that is not set up for extra credit. The total possible extra credit points it can contribute is determined by its weight in the gradebook:
relative weight in category × category weight in gradebook = extra credit points
The item’s relative weight in the category will never change, even if the category contains unscored items. But what about the category weight? Remember, if this category contains scored items, but other categories do not, then the weight of the category will be increased. In this case, the weight of the extra credit item in the gradebook will also increase--and so will the total possible points it can contribute.
Alternatively, you may have created a category that is set up for extra credit. The weight of the category in the gradebook determines the total possible extra credit points it can contribute. This weight never changes, even if other categories do not contain scored items. But what about the relative weight of each item in the category?
If you selected “scale extra credit” when setting up the gradebook, then the weights get adjusted just as they would for non-extra credit items: weights of unscored items are ignored, and weights of scored items are increased to equal 100% of the category. So, the extra credit contribution of the scored items will be greater than what is displayed in the gradebook.
How “drop lowest” settings can affect course grade The “drop lowest” setting for a weighted category can also affect course grade, and in the same way as having unscored items. When some items are dropped from a category, the CLE increases the relative weights of the other items to equal 100% of that category. So the weighted scores of these items will reflect a greater item weight than what is displayed in the gradebook.